! 
THE PLANT COVERING OF OCRACOKE ISLAND; A STUDY 
IN THE ECOLOGY OF THE NORTH CAROLINA STRAND 
VEGETATION. 
By TnoMAs H. KEARNEY, JR. 
INTRODUCTION. 
In Octooor, 18D8, in tho oonl"''' of field work for the Ullitea States 
Depal'tment of Agricn1t.llI-e, t.ht· wl'it~'l" Flpent five days upon Ocracoke 
Island, NOl'th Carolina. Owing t.o it~  limited size, it was possible, 
even in that short time, to t'xplol'e somewhat thoroughly a consider· 
able part of the isll\l1<1. It, i" t.o be regretted that visits wore not 
mafie t,o the loru1lity earlicl' in 1lte Heason, so tha.t the phenological 
development of th~ vegetal.ion oould 00 studied. Howeyer, ''" most 
of the eharacterist,ic plants of Out' southern Atlantic stram1 are rather 
late in mat.uring, it is probable that a bet,ter season for a single yisit 
could not have l)een chosen. It was of course impos..,ible t,o make 
any valuable observa.tioll~ upon fecnnuatioll and dissemination, 
important a. these subjects lire (0 the study of the geographical dis­
tribution of plants. What is Raid here of OCl'IIcoke will doubtless 
apply, in a general way, t,o t,he ot,I1£'1' sandy reef~ of the North Citro. 
Hna coast. 
The object of this paper is " st,udy of the ecology and geography of 
the vegetation of the island, the ~evCl·n.l divisions of t.he Nubjel't l)('ing 
presented iu the following order: 
(1) Climate; (2) physiography; (3) geology 1111<1 soils; (4) the plant 
formations, theircompositioll and physiognomy; (!i) ecological fOI'JIls­
adaptations to Nlvironme nf.; (G) a.nat,omy; (7) phytogeographical 
affinities of the flora. 
The nomenclature uReu is mainly that followed in Bl'itton and 
Brown's Illustrated Flora of the Northern Unite!l States aUll Canada, 
but, in order that t.hose who are int.f'rested in ecological work and aro 
not familiar with t,hisllomenclatul'e may find nodifticultyin recognizing 
the species described, the names useel in "he later works of Gray and of 
Chapman are quoted in parentheses. A full list of 611 plant, collected 
or observed upon the island is appended. a.nd here. again, familiar syno­
nyms are ci~ in pA.renthese~. A list of the works qnoted, with their 
full titles, is given at t.he end of the paper. 
In the preparation of the anatomic,,1 portion of the paper, 1111'. 
261 
262 THE PLANT COVERING O~' OCRACOKE ISLAND. 
Tbeodor Holm hI\.. rendered valuable 88Sistance, a nti I.e has kindly 
furnished the drawinb'" for figure. Nos. 1 to 8,17, and 18. The other 
figures were dra'Yn from nature by the author. 
CLIlIIlATE. 
The following data have been obligingly furnisbet! hy the United 
States 'Veather Bureau. The observations wero made .. t tho Hatteras 
Station, only a few miles nort h.",,,t of Ocracoke. 
TElII[PBRATURB. 
R eadings were taken in the shade. 1 The observations at Hat,teral'! 
cover 8 period of about twenty years. Tht!' average number of days 
per annum with a temperat,ure exceeding 6° C. (4:3° F.) is :3G5, while a t 
Norfolk, V"., the nnmber is only 2D5. The sum total of (emp,· ,·"turcs 
above 6° C. during the year a.verages 3,74-004° C. (U,74-!)O F.L which 
is notably higher th",. the Norfolk figure of 3,35904° e. (Ii,O!i. lJo F .). 
The normal mean wmperaturedul'ingthe liix consecutive hotl.eAt weeks 
of snmmer is 25.9° C. (78.6° F .), liS compared with tlw slightly higher 
mean of 26.3° e. (79.3 ' F .) at Norfolk. 
The norm III annulIl temperature i8 16.3° e. (61.4 F.), a. eOlllplll'ed 
wi th H.8° e. (58.7 ' F.) at Cape Henry, Virginill, 15.00 e. (5U. O' ".) at 
Norfolk, Va., a1ll117.2' C. (63.0' F.) at Wilmington, N. e. 
The normal monthly temperatures aro "" follows: 
-------I-
Deo
- - C '~-F !- ------'-Oe----,~- -; 
..... • • Itl"UOH C . ""' .. . I I , 
. . .- ._--
January . -... _----- -_ . _-- i ,6 "".1 July ...... . .......... ___ . 2;).5 • •• ...
F~bruary .•.... ___ . _____ . , .. .. .• August • ••• •• • • •• •• • ••••• .J'). _, - . ii,' Marcb .•• _ . ______ ________ . 10.0 00.1 , September ..... ......... ')oJ .J , i3. 7 , -.. 
, Aprll .•..... __ .... __ •... __ If.O 57.2 , October ll'! . O 61.5 , ...... .... -.- .... 
May ••••. ..• .• __ •••••• ___ . 19. I 66.' 
, 
November 1;], 1 :\i. 6 , ....... -_. -- .. 
• June 23.3 7'.0 o..'eemiJer .• .- •.••.. __ . _ -- I II. n  "8.2 ................ _---- i 
The normal daily range o( temperature for the whole year nmounts 
to 6.3° C. (11.3° F.), 88 compared with 8.2° C. (14.7° F.) "teapc Jlen.·y, 
8.8' C. (15.8' F.) at Norfolk, "nd D.6' e. (17.3 ' F.) at Wilmington. 
The normal daily range::l for each month ",I'e Ilol"; follows: 
• 
, 
DeiToefJ C. De&,ree~F. 
----- - --,,-_.- _ . . __ ._. - " ' - , -- - _.-
7 0 i January . . ...... ... ... .. . 
February .... . : ....... __ . 
Marcb .. ............ ____ .. 
April ...... __ __ . ........ .. 
)lay ...... ... ... ........ . . 
JUDe ...... ... __ __ ..... __ . 
... I f 
. . , 
j . ... , 
6.9 I 
e .• 
.
., . 
••• 
1~.8 . 
12.9 
12.5 
11 .5 , 
10.3 
July . ... ... .. ...... ... _. _j 
Augu~t ..... . . ..... ...... 1 
8eptembE:' r ..... ..... .. .. 
~ )cto1.J,.·r ......... __ .. __ __ 
No\,ember . .. .. . __ ...... 
Deoom oor . ....... __ . __ .. 
a. ,"i 
• 1 • 
... I , 
... ;1 • • 
• 
• • • 
iI . I I 
d.:1 I 
.., I 
-
- --- - .---'-- ----' - - ---- .- -_ .. -_ .. 
.. - --
10.0 
0.2 
g . • 
10. 2 
1l . 3 
12. 8 
IConaequently they do Dot repref!ent the temperaturo to Which magt of the veg&­
tatton is actually exposed. being subject to insolation during the hours ot 8un· 
shiue. They are chiefly valuable for purposes of comparison with other climates. 
• 
• 
• TEllPERATURE CONDITIONS. 263 
The absolute maximum temperature observed was 38.S· C. (102° F.), 
as compared with 30.4° C. (103° F.) at Cape Henry, 38.So C. (102° F.) 
at Xorfolk, alld aOAo C. (103° F.) at Wilmington. 
The absolute minimum temperatureohserved was-13.3° C. (8.0° F.), 
"8 eomp.u-ed with - 15.0° C. (5.0° 1".) at C.\pe HeDl"Y, -IU.Uo C. (2.0· 
F.) I\t Norfolk, and - 12. 8° C. (n.o· I'.) I\t Wilmington. 
The ahsolute monthly maxima and minima are as follows: 
Maximum. I Minimum. ){Qntb. 
[h)i"TW8 C·l Dee tees F. Degr~C. Degl"OO8 F. 
January . _ .... •••• • • .. . . . _-_ ....... . ..... ..... -_. __ ._. :>I. , . ,. -10.0 
" Febru.ary. =!!. H ;a -11. • 11 _. -._- -.. .... --. ,- ------ ---.-. • •• ••• • • -. -- • 
March . - ... -
------ • • •••• 
. _ .... 
.... -- -.. ... :.\1. " >5 - 3.:3 .. ---_.- -.... -
April -. -.... --- _. -· _ .... -.. _ .. • • • •• • • • • •• • . . ------.... :JO.O .. 
-
0,' SI 
May -.... . - ... -..... • • •• •• ---------- . -. -..... . _., ... _- 319 00 6.1 43 
June ... _ 
.. --'- --... -... ................... .. ..... -.. -- 3l:I .~ It" I:!.X M 
July . . . . . . . . . . . . . ..... .... .....• .. . ... .... . ... .. . .... . :r." •• 99 111. I 6' 
August. . ..... . . . . . " "" ........... ... ... .. · . . . . -.... "", 
, 0; Ill. (j .. 
8ept€'mber . ...... .. .... .... •••••• . .... .. ... · . . ---_._ . J);i.O 
'" 
10.0 60 
October . ~ ,~ 00 • <2 _ ..... . . . . . ........ . .......... • ••• •• · ....... .. • • 5. ') 
November 
'" 
I .. " " 28 .. , -. .. """ " .... .. _-_ ... . ..... · ... .. . . , . - . . i .' . 
December , .... tS 7:j -la.a B . . . . . . ...... .. ... _ .... . . . . . . .. · ... · . . - - - .... I -. 
, 
• 
. 
The average date of tho lawst killing frost ill I'3priug' is February 
25, as compared with March 19 ntCape Henry, March 26 at Norfolk, 
and March 15 at 'VilmingtplI. The latest recorded was April 5, as 
comparoo willi April 19 at Cape Henry, April2G at Norfolk, and April 
20 at Wilmington. 
The average date of earliest killing frost in autumn is Dece-mber13,. 
as compared with Novembe.· 14 at Norfolk ant! Cape Henry and 
November 12 at Wilmington. The earliest killing frost recorded was 
on Novembet'12, as compared with November 14: at Capo -IIellry, Octo~ 
bel' 15 at Norfolk, 1111<1 October 13 at Wilmington. 
From tho above llata the temperature may be cha,racuH'izell a::l fol· 
lows: 'Varin, but not excessive, with a considerable sum total of 
effective tempel'atureM during the growing season, and usually mild 
temperatures during the very brief dormant pel'ioc.1, The normal 
tempeI'attlre is at least O.So C. above freezing point dUl'iJlg every 
month of the yea-I'. The normal amount. of da.ily nt-1'ia-tion of t-em· 
pera,turc i~, ILeum'ding to the season, from 5° 1.0 7° 0 ., a, relatively 
very small range. The period betweeu t.he ft\'cl'ago aates of the 
earliest killing frost in autumn and of the lat.est, in !:.'pring, which may 
be (,aken as very roughly coinciding with the .1orlllaut period of most 
of the vegetation, covers only seventy-foul' clays. 
\ , 
264 THE PLANT COVERING OF OCRACOKE ISLAND. 
SUNSHINE. 
The observations cover a period of nearly thirty years. Normal 
annual sunshine,1 stat<ld in percentages of possible sunshine, 54, as 
compared with 52 at Capo Honry, 51 at Norfolk, and 5~ at Wilming· 
ton. The mont.hly l",rceutages are as follows : 
--- . -_ ... _. -- .--- -
Per Month. cen Month. 
Per Month . Per t. cent. , cent. 
. .. 
-
May ••... ••••.•. ____ •.•. Ii!! I September . . , _. ______ .. 1 116 
----- - -
J&Iluary ...••... ...•.... ~ 
Febl'11&ry . ___ . ___ •• ••••• 4 , June . • ....•••...•.•.. .. M Octolx>r • ••••••••••••••• 116 
• 
. , J uly . . ..... . . _______ ... . 55 November IS< .. .. __ ... __ . March •••... ____ ._ • •.. .. 62 
);1 April. ..... ___ .... .... •.. f AUIl'URt . ----. _ .. _-- _ ... 52 I December . ••..••...••. 113 
. 
- --- --
Normal annual snnshine, stated in hours, 2,:192.2, as compared ~th 
2,314.6 at Cape Henry, 2,270.1 at Norfolk, and 2,312. 'i at Wilmingt.on. 
The nonnal mouUlly numbe r of hotH'S of t:mnshine MI'~: 
Month. Mouth. I I I Hour~'I ' 
- - ----,-- ,. ---
1«.7 ] May . ... . . . . .. . ........ . 
143.; ; June . ... ............ .. . 
January ............ . .. . 
F ebruary . _ . .... . ... .. . 
M.reh .......•.. .. . .... un. " July .... ....... ..... ... . 
ApriL ............ ... : ~,,': I 211l.0 ! AugnMt .......... .... . . 
..... - . . . 
Mouth. Hour&. H I our~r 
--- --1--
256.2 Septemhnr ._ ... ...... . 
t:l8. D October . . .... ..... ..••• , 
2&3. 1 ; No\·(·mber . ..... _ ... _ .. 
216. ~ I Dt'eem b.>r .......... .. . 
II 
"".8 
:m.O 
1 6~. ' 
100.6 
These records yield the 1~'SUJt, that the normal annual percentage 
of sunshine is low compared with tlt"t, in mnch of the territory of the 
United States, especially west of the JIlississippi Rkcr; bnt it is not 
much less than that prevailing in otlter parts of the Sout,heast.ern 
States, while it exceeds the percentages given for the northern portion 
of the Athllltio slope. 
ATIII[OSPHERIC HUIII[IDITY. 
Thi~ iR stat.ec.l in percent.nge~ of possible satllrlt..tion, which of course 
varies at different seasons with the temperature, etc. Annual (for l\ 
period of soven years), 81.4 "" compared with 74 atC .. pe lIenry, and 73 
(during nine years) at Norfolk and \Vilmington_ Monthl.,-, as follow", 
I • I I Per • P or Per Month. Month. Month. cen\.. eent. oent. 
--_.-
- -
, 
• • • January • 
" 
M.y . ... .... _ ........... 
'" 
September . ....... ..... 81 • ...... -_ .... .... , 
February ...... _ . .. .. .. . 81 June &1 I Oetooor ••••.. . .... __ ..• 81 ...... ... ..... _ .... 
• 
M.arch ._---- -_._ .. .. .... 71l J uly ........ _ ........... 83 No\"emher . .. ....... ... 71l 
.ApriL ... ...... ... .... . . . 80 · August .1 .DecemheJ" ., ......... ....... . .. .. ....... . , 1 _____ , _ _ _ ._. _ __ _ ----1C _ ___ _ _ __ -'--- __ 
The annual pereentage thUA shown is greater t.han t.hat recorded 
for al1yother Rt .. tion in the United States, excepting those in the 
I These figures only approximate the real values. They are derived from stati ... 
tice of oloudiDe88. 
-
RAIN~·ALL. 265 
Puget Sound r eg-ion, aud eYell there t,he excess oyer the Hatteras 
figure is not great. Moreove r, this humidity is distributed thronghollt 
the months of the rellr with remark"ule uniformity, the variation 
between any two months amounting to not more than 5 per cent. 
PRECIPITATION. 
This i8 stated in centimeters and inches. Annual, 150.4 centimet~rs 
(G6.41 inches), as compar •• d with 1~5.G celltimetel'8 (52.:!4 inches) at 
Cape Henry, 125.0 centimetel'S (5~.1 iuches) at Norfolk, and 1:)0.4 
centimeters (M.3! inches) lit 'Vilmington. Monthly, as follows: 
. --- -~ . -- - -
Cen- Inch· . Cen- I Cen- Inch· Month. time· M onth. time. Inch- Month. time· 
tel's. es. ters. 6S. ters . e •. 
-- -- --- . 
- .. -I • January .. _____ ..... 14.2 5.91 May 1I.n 1.410 I: September ..... . __ 15 ... n." . -..... -------. 
February .----..... 10. j' • . 01; , JIIIl~ ... ... _ ...... . _ 10. D ' . 51 {)c-tober .• .. __ . __ •. 14.8 to, 1;-
March . __ ......• ... . 14.0 6.10 .Tulr " . .... ___ .. _ ... I.i. 4 0. 43 NO"emoor . . --. . -- 1~ . • ;~. 18 
April .. _._ .•.•.. •.. . , 11.3 , ~, . ,- August ___ . __ .... _. 15.2 o. :Vl Decemher .... _____ 13. 1 
, 
' ,-.1. , 
I • • • • 
-
-------
.. _-_ .. • . -
-
The average annual number of rainy (lays is 123.8, a.s compared 
with 125 at Cl\pe I1l'nry, l:n':J at Norfolk, "nd 128.8 Itt Wilmington, 
The a,'erage monthly Hnmh~ ~l' of rainy days is as folloW8: 
- -
1 . 
: Dar~· ! 
-_.--- .. -. - - --- .... -- ---,----
, 
Month. Month. i Day>;. 
, 
Days. Montb. 
, 
J anuary ..... ~.~~ .~~~ -la.ll , Ml\r .. .. __ __ ~ .. - - _.-~.·~. -. 10.O i _~.p~~ber-.-. _ .•.. =[--" ].;.; 
February .. _ .. ... .... .. 10. 2 · JUD\! .... . _ . . _ . ......... 9. 6 , October .... .. ___ . ___ . . _ 7. 5 
, ' 6.; Mareh ______ ... ..... _._. : 11 .9 :, July .. ....... ____ ... . .. . 10.2 1 No!;'emlwr"'--'-"--" l 
April._. ________ . . . . ... _. ! 8.4 : AUil'u~t ____________ .. .. 10. 2 , Docernlltlr .___ _________ !US 
... ____ ... ____ I ~_ ,____ _ .. __ .. 1 ___ : .. . _ .. __ ._ ...!.I __ 
At Hatteras the precipitation consist.!ol almost ent.irely of rain. Rain­
bearing storms Ilsnally approach fl'Qm It wt~sterlydll'ection. ,"Vi nter mHl 
Api-ing rains are usually of light inte nsity and long dlll'1tt,ion, while 
those of the .summer and fan aI'€' mOl'e often brief and torrential in 
character. 
The J"esult ,~ yit'wetl comparatively are as follows: The Ilorllu\l 
finnllltl ra.infall is remal'kably hea,"y, ('xceeding that. at the nearest 
station, 'Vilmingt.oll, hy 30 cCllt.imct('l's. Only on thE' const of 'Vm~h­
ingtoll and Ol'l..!g"OIl doe!i the tota.l l'Hiufall wit,hill the limit-~ of the 
United State~ notably exet'ed that uf Hattel'us. Thn normal "aria­
tiou between t,}-le month of least and t hat of greatest rainfall does 
• 
not exceed 5 centimetel's, so that in onlilla.ry seasons periods of 
drought do not occur. The helt,·ie.t r"infallOCCllI'll in the months from 
July to October. The average lluml><'l' of rainy <lays is large, about 
one-third of the days of the year, antl is distributed with rell\til'cly 
great uniformity, varying from 6.7 days in t,he month of least to 15.9 
in the month of greatest Illll11be .. of rainy days. 
Of dewfall no statistics could be obtaincU. 
266 THE PLANT COVERING OF OCRACOKE ISLAND. 
WIND. 
The Novel'age annual maximum velocit,y of the wind is 21.4 kilome· 
tel'S (1:J.3 miles) per hOllr, a.~ compared with 23.2 kilometers Itl. Cape 
Henry, 15.1 "tNorfolk, and 15.4"t Wilmington. The .werage monthly 
maximum velocities, ~:.ated in kilometers and miles, al"e as follows: 
IKHo- "i. i •. " -I Kilo-
::\Iollth. me· lIiles Month. me· Miles- Month. me" Miles 
terll. to ... i terfl ".,_ .. _- " 
- I i , • January ... .... . .. .. 25.0 105. 5 Ma, ...... -- -----.. ".3 12.6 September. __ .. .. . : Ij,2 ]0. 7 ; 
Febl'uary .. .... . --. .... l b. ! June . •. .. . ... . _ ..•. 21. a 13.2 
• 
October _ ...... . •.. lB.' n.' 
M"rch . .... ... . .. .. . 
"" 
16. " July .. . . . . .. .. . . . .. ]8.6 
, November ___ , . ... 18. 8 12.3 11 . 5 i 
• 
ApriL ..... ..• • ... . . U .2 1.'). 0 Au&'ust • ••••.•.. ___ 19. 7 I'll ., , December._ .•. .. . . 24.0 14 .9 ~ . .. :1 
--- "- -
In regard to dil'ection, thu winds uf midwinter are usnally fl'OlIl the 
north , while those of midsummer are usually from it little west of 
south. 
As thus shown, tho average vc loeity of tho wind is considerable, and 
the umOl1nt of its variation fl'ollllllolith t.u month is r'emarkablyslight. 
The highest l\.vel'f\.ge of conrse lU'C\',dls in wiuter and {~1\rly spring, In 
midwint er, whell the winds al'o nOl'uHtlly strongest and therefore most 
affect lhe peI'euuial, especially the wooely vegetation, their prevailing 
direction is almost due south (from tho 110I'th), henct", in tho case of 
Ocracoke, from t.he mainhuH.l. 
In regard to temperature, rainfall, and atmosphel'ic lllUllidity the 
climate of Ocracoke and Hatteras is suitable fot' a. vigoro lll'l fOI'l'st 
growth, But the exposure to st.rong winds, and the peculiar soil con· 
ditiollS, neutl'Rlize these fa"orabl e factors and give it II. typical ~tl'and 
vegetation, which much resembles t.hat of deserts. In the Jle ighbor­
hood of Norfolk "ne! of Wilmington, where conditions of 1" lIllle"ature 
and of humidity are really somewhat leSl! suitable 1 han Itt Hatteras to 
the most luxuriant de-velopment of plants, the virgin growth is almost 
e verywhere dense forest, because there the inimjc.~al conditions are 
absent, 
PHYSIOGRAPHY. 
OCl'ucoke Island is purt of that lOIlg' chain of narrow sand J'eefs 
which fl'illgl'S the sOllt,hel'll Allauth~ Coust of the UnitA.~d States, and 
which fol'Ul s t.ht~ (jc;l:it.el'n hal'l'h: I' to a. series of a.lmost. lalld-Ioe kc.'ll ha.ys 
and sounds, Ocracoke lies in longit.udo 7(j° west alld laLitlllh~ :l5° 10' 
north, und is therefore somewhat south of the ceJltt'I' of t.he N ol'th 
CHl'olinn. coast. It is separated from Ha.t.teras Ht.'e f by till' n.B kilo­
meter (one.lul.1f mile ) wlde st.I'nit kllown as ll;\u,(,I I'uS Inlet" and (l'(lIll 
Portsmouth, the next island below, by OCI'Hcoke Inlet, :; kilometer'S 
(nearly 2 miles) wide. Ocracoke itself i. abollt 26 kilolll ~lel's (16 
miles) in length, and extends from that great uulge of the coast line 
GEOLOGY m' THE IST.AND, 261 
known as Cape IIatteras, in a southwesterly di"eetion. The island's 
greatest width near its lower end falls short of 3 kilomete ,'s; the Itver· 
age width is only] kilomt~te l', while ill l)laces it is lwen lIal'l'OWel'. 
Outside rolls the Atlantic, while between island and m"inland .tretch 
the waters of Pamlieo Sound, here from 30 to 45 kilomete .... (IS to 27 
miles) wide. Pamlieo differs from tho shallower Albemarle Sound to 
the north in the important respect that its wIlter is alwIlY" salt, while 
Albemarle is normally fresh. 
Near the southwestern extremity of tho island a bro",] expanse of 
tidal Oat separates the highe,' land of the villa.go of Oerncoke from 
the Atlantic beach. One and one·half kilometern or so toward the 
northeast this lagoon disappears, ai,,] dry land extends from the tlat 
Sllndy beach and the salt marshes which border the Sound to the 
dUlles which front the ocean. Into these marshes penetrate tiny 
c .. eeks, whose ramifications cut the lower part of the island in all 
directions. Almost the whole area i. divided between sand strand 
and tidal m .... sh. !\Iuch of it is only 1 meter 0" Icss llbove normal 
high tide and subject to overOow whell stmllg easterly gales arc blow· 
ing, or when stiff breezes from the o]lposite qnllrlRr mass the waters 
of P .. mlieo Sound against the western shore of tho island. The high· 
est land on Ocracoke i!~ l'epre8ented by sand (tunes often 3, sometimes 
8 mete,'S high. These aro ".u .. lly regular in form and fairly well 
fixel\ by the vegetation. Those that abut UpOll the outer beach Or 
rise amid the mud fl .. ts are particularly regular .. nd dome·sh .. ped . 
• 
GBOLOGY Aii'D sons. 
Of the geology of Ocracoke a",\ its neigh hOI' Hlltter"., we hllve 
comparatively little knowledge. Shltle1' I has ad ,"anced the theory 
that these reefs were built np from the c1et,·itu. which resulted from 
the glacial excavatioll of Delawal'e and Chesa(>eakH ImyM. Kerl'~ 
descl'ibes Hatwras as a "sort of delta. " ·"The actinll," he says, "of 
the titles and ocean currents, the Gulf ~tl'ealll awl Arctic current 
lll~eting at this point, accumulates upon Hatteras the river silt which 
reaches the sea. by way of the Chesapeake as well as that of t,ho Tiye~ 
Wllil'h discharge theil' bnnlens through t.he inlets about. this point and 
southward. * • * Hattel'as is Hot a. modeI'll phenomenon . It is 
Ht h.'Rst as old as t.he Cretaceous; the Quaternary a.s well a~ the Tel'­
tim'y of this coast region of North ()n.r·olina arc laid down upon an 
eroded surfnce of Cl'etaceons rock." From meaSUl'cnwnts elsewhere 
mtHlc, the probable depth beneath the surface of the \J re!<.ceou. for· 
matton on Hatteras and Ocracoke would 00 somewhere hetween 200 
and 300 meters. lam not aware that borings of any('onsideraille depth 
-
! Proc. Bost. Soc. Nat. Hist., vol. 14, pp. 110 to 121. 1872. 
iBu\' "'~ash. Phil. ~oc., vol. 6, lip. 28 to 30. 1884. 
• 
268 THE PLANT COVERING OF OCRACOKE ISLAND. 
have been made upon these islands.' I{err further sl RI~s that" the reef 
is increRsing in continuity Rud bl'eRdth." But this is not the gen­
eral opinion, for it is said that there is to-day water of considerable 
depth where houses stood upon Ocracoke within the memory of H\'ing 
men, and it is "I.ate,l' that" a fine fig orchard an(l many peach !roos, 
-with n fine potato pat.eh and garden," occnpied oarlier what. i8 ' ]10W 
Hatteras Inlet. That the present tendeney of this wholll coast line is 
one of subsidence can hardly be disputed. 
Beneath the superficial Recent depositoS of dune Mnds and salt ­
marsh .ilt which covel' the greater part of Ihe island lie the santls 
an(! cIi.ys of the Columbia formntion, which extend 1<> 1\ considerable 
bnt unascm1,ai ned depth. This and the Recent acclllnulations are 
the only geological formations of this part of the coasl,1l1 plnin which 
ne~<l be considered in relation t.o the existing plant cown'jug. 
}:xcepting the arcas occupied by creeks and salt mnrsh, Ihe ""il of 
Ocracoke is 1\ fine white marine Mnd, almost everywhere dt~voitl of 
any considerA.ble admixture of hnmuA. Only. in the Jiye·oak gro,·es 
is there enough vegetable matt.er present to give tho sand a g-rny 
color. Thero is doubtless some quant,ity o f ralciulll ca.l'bolmt(~ in t.he 
soil, owing to the }ll'esenoo of small particles of shells WRsh(·tl up hy 
the waves and scattered by I,he wint!. ' 
As much of the islaucl ir-. !Subject to occasional inundation alHI to 
the deposition of spray by tho winds, t.he ~oil content. of sodium ('hlo­
rid must be consichwably greatel' at times than in ol'dhutl"Y inland :o;.oi1s." 
ThBre is no lack of moisture in this sandy subst,('a.t.um. En.·n ill tho 
driest looking beach sand, watel' usually stands lit a ,lepth of only I.'i 
to 30 centime!,ers (6 to 19 inches) from the surface. The .nperficilll 
lI.yer of the sand acquires It great amouDt of heat on sunny day' and 
becomeH thoroughly desiccated, in which condition if, i!ol snbjet>t to 
being blown about by the wind, its degree of coht'rency fl(~pent1illg 
upon the character of the vegetation, At night, however, Sfllic1 gh-es 
up its heat rapidly and ab~orbs much dew, if conditions are fayorahle. ·~ 
The soil of the salt marsh, which appears 1.0 be usnally a thin ~hl~(~t, 
1 Tbe succession ot strata tn the North Carolina coastal plain, where exposed 
in the valleys at the Neuse and Cape Fear rivers , is given as follows , beginning 
wltb tb. old .. t , 
(1) Potomac gravel, Band8, and clays. 
(2) Cretaceous sands and claY8. 
(8) Tertiary (Eocene and Miocene) marls and clays. 
(4) Lafayette (yellowish and brownish sands and loama). 
(!\) Columbia sands, gl8vels, and clays. 
"W. L. Welch. Bul. EBSeX Inst .. vol. Ii, pp. 3i to 42. 1~. 
~According to Contejean (Googr. Bot.), the proportion of calcium carbonAte 
thOR 8tlpplied to tbe strand aoils is insignificant except near the \vave limit, the 
particles being 800n dissolved by the carbon dioxide contained in rain water and 
then washed down through the readily permeable Roil. 
4 Sea. water contain!! from 2.7 to 3.2 per ceut of NaC1. 
'Warming. ~brlluch. p. 66. 
ECOLOGICAL GROUPS. 269 
of fine, brown silt overlying a stiff, bluish clay, contains organic mat· 
ter in considerable quantity and is therefore capable of supporting a 
denser plant growth than is found upon the sands. It is of course 
saturated with snIt 01" brackish water. 
There is no outcrop of allY kind of rock on tlw island. 
THE PLANT FORMATIONS, THEIR COlll!POSITION A.ND PHYSIOG­
NOn. 
The various assemhlag~s of species and individuals which make up 
the plant covering of Oci'acoke Island Illay be classified as follows: 1 
J. Sand·strand vegetation. 
1. Tree:ess (open). 
(a) Beach formation: Croton·Physalis associat;on. 
(b) Dune formatiou: 1 Uniola· Yucca association. 
2. Evergreen trees and shrubs. 
(a) Tree formation: Quercus virginians. association. 
(b) Thicket formation: Ilex vomitoria association. 
II. Salt·marsh vegetation. 
1. Creek-marsh (closed) formation. 
(a) Spartina stricta association. 
(b) Juneua roemerianua association. 
2. Dune-marsh formation; Lippia-Monniera associa.tion. 
3. Tillal flat (open) formation: 8esuvium-Tissa association. 
III. Pastures and ruderal plants. 
IV. Cultivated plants. 
It b; not to he supposed that the several groups are always ot· even 
cOlHlllonly sharply defined_ On the contrary the trallsition from one 
to another is almost a.lways gradual, so that portions of the plant 
covering are (lifficult to classify. Nevertheless, the formations and 
associations are distinct features of the landscape, easily l'ecognizq.ble 
by any observeI'. 
-----
-----------------
1 It has seemed best to nse the word" formation ., in the same sense as employed 
by the German and most other plant geo6raphers-i. e.. to designate the 
larger assemblages, For more restricted groups, whether cOIllI)()Joled of one or 
many species, the term .; association" is to be preferred. The nearlye;iuivalent 
German word •. Verein" is used as a translation of the Danish" Samfund" in 
one of the most important works on the subject (Warming, Lehrbuch) for the 
larger assemblages or formations; but, in the want of a better English word it has 
been thonght expedient to employ" association" for the moro re!!tricted assem­
blages, which arepecnliar to each biogeographical area. While the formations are 
purely ecological elements which recur in the strand yegetation of other regions, 
being for the most part closely dependent upon topographical features, the asso­
ciations are often quite local; and owe much of their character to the particular 
groups of species which compose them. 
~It is not possible to distinguish bere several dune formations, such as occur, 
for example, on the coast of Virginia. 
-270 THE PLANT COVERING OF OCRACOKE ISLAND. 
SAND-STRAND VEGETATION. 
TREELESS, (.PEN Jo~()RlIATIONS. 
BEACH FORliATION'. 
This formation occurs along Pamlico Sound, occupying the flnt or 
gently sloping sandy belICh, especially toward the lower cud of the 
island. The species are IIlmost all herbaceons amI uSllally forlll lin 
open veg~tation, lea"ing much of the soil uncovered. The most 
abundant i~ C-roton 'Inarilim11.s, which sometimes grows rather closely, 
excluding other species. By reason of ita silvery-gray color, dlle 10 " 
close, stellate, scale-like pubescence, it is ODC of the most eUIlspicllQll8 
planta of the island. It is usnally stont and often milch-branched. 
Another noteworthy plaut is Physalis viscosa, a perennial herb, with 
slender roots, sometimes 1.5 meters long, creeping near the .urfllce of 
the sand, and Bending up at intervals short leafy shoots. It.~ color 
varies from green to gray with the density of its co"~ring of branched 
hairs. An int.eresting feature of this formation is the occurrence in 
places of diminntive thickets only 1 to 3 decimeters high, composed 
chiefly of IIex vomiforia (J. cassine of authors), Za>1fhoxylon "/al'O­
Mrcui:is, Juniperus 1."irg-iniana, with leH.vesonly of the spreading form, 
and Op,."tia pes-ofFfvi, with its long spines. Among other species 
belonging to the beach formation, there lire of allllual herlls Eu­
phorbia polygonifolil" Trip/osis purpurea, a ~anescent form of S,,/a­
num nigru11l" a lnrge-fl-uited Xanthium, n.ntl 8,,18010. kati, the last 
being the most abundant.; of perennial herbs Teller/IOn 1II:v:;71ii, with 
slender stolons fmd white-tomentous )owe1' leaf stlrfa.ce, Chlm'is 
petraea, with decumbent eulms, rooting at tho nodes, PaH'icum 'fi e/(­
ranthum, and occ"siolllllly CI/priola t/acty/oJl (CUI/odon dOl'/yloli 
Pers.); of woody plallt~'J Rubu.'l trit-/alis ntHI SlJ1iln.i.~ lWlIO-l1o.r oc(,ur 
here and thero, with pl'iekly st'(~Ill:-: trailing ow'r tht~ 8l\wl. 
])J.jNF. FORMATIOX. 
Open (hmes aTO occnpiNl chiefly by t.he halUls ollw ~('a. oats, r~"jol(l 
paniculai((, the most charneteristic strand plant, of the SOllt.h en~t(> l·n 
States. The low, l'onnded dunes which ri~e fl'om a bare IU,.,hhl.'" 
shingle on the ocean ~ide of the island, and here Hlul t.here in the 
midst of the tidal fiatg, support 110 ot.her ye~etat.ioll. The Ipaf,\' 
8hoot~ of thi~ grass a.l'O produced in gren.t nbulHlanee, but, ftoW(']'illg' 
branches al'c much lessllullHwmls. 1 .1 Iu,lllenbel'fJ ia filipps is ahlllHlallt 
on a.nd among t.lw dUlles, it~ dolicat.o purplish pani(~les, swa.ying with 
tho lightest bn'ath of ail', prt'stmtillg' fI, most beautiful app(·IlT'n. llt·(~ . 
It is almo:-lt. the only l'cspitose plant, of the island, and grows in 
tuft.s lhat, am sOlllot.ime~ a decimetel':-l in dhllllct.PI'. Ratlwl' small 
- ------- -----_.. . .. -.------ --
lIn this respect the Untola resembles Ammophila w·t'l/(u·ia, which btkes its 
place farther north. 
TREE FORMATION. 271 
plants of Yu cca 1170ri080, with tleshy I·ootstock. often exposed by the 
shifting of the sands, Rre frequent Oil the le:o;ser dunes. The single 
speciuH:'1l of }"Il('cn rr.IOtfolia observed was o\'er ~ mett"I'S high, wit,h 
~tem branched Meyeral times above the !;I'OUlHJ. Both species haye 
exceedingly h, .... l "nt1 sharI) spinolls le"f tips. On some of the higher 
dllnes depauperate plants of the shrubby Myrico carolinell"i., most.1y 
only :j to G decimeters high, a ... ,ocillte with the Uniol". Of secondary 
importance in t,his association are two perennial gras~s, Pan-rcllm 
amarurn minu .. ,,"d Sp07'lina palel!8 (julleea); a. well "S " probably 
biennial thistle, Carduus spillosissi"''''' (Cllicus "orridulus); and 
several other herbs, among them Uw whiw-~el'iceons Uenoi-hera humi­
Jusa and Croton maritimlls. 
EVER(lREEN TREE AND SHRuB FORMATIONS. 
TREE FORMATION. 
Scattered over the island, bnt preferring the higher dunes which 
occupy its inner side, are small gron~s of liYe oak, Quercus l'irginiana 
(Q. ·t' irens), either in pure assoc-iatioll or mixetl with some. other trees. 
The ollks Me lIslIally 6 to 9 meters high anti 3 (rar~ly 7t) decimetel"S 
in diameter. Those on the lIol't-hel'u edgf:ls of the groves have trunks 
st,rongly inclined t.oward UlC south, and, a:-; a. consequence of the denu­
dation of t,he branches on the windwal'il ~it1e, t.he whole crowu of 
foliage lies to leeward of lhe axb. One conhl not desire a better 
indication of Ute prevailing- direction of strong winds in the )'egion. 1 
The branches, gnarled and twiSt.l·d, are clad with HUmet'OUM li<:hens, 
chiefly Usnea barba/a, and with occasional small wi sps of Spanish 
moss (Tillamlsiu uS1leoides), which pvidently maintnins but a precari ­
ons foothold on the trees of this wintl-expoged island. 
Altogether the aspect of the g)'oYes is rathel' wei rd and somber. 
Often asgociateu with t.he oaks a)'e ~1Il<l1l tl'pes of J.lIytica ce1'lj'ern, Zan­
thoxylum clava·hen:ul is and Ih:..r. '/'ow i/oria, aU of about the same maxi­
rnu m size ((j metul's II ig-h and ~ dl'c i II1ct.el'S in diameter), and occasionally 
Juniperus riryiniana, which I'al'e ly attains n. lwight. of' meters find a 
diameter of 3 d('('i Illetel's. LianHs ;ll'l' spa l'ingly I'epl'es(>nt~d by Sll~ ;Ia:r 
bona-no.r., rilis (u'.-;/'iI'01i8, and Rhus radieans, 1\11 thl'ee s pecies SOllle­
ti lIl e~ attain i ng ('oll:-;idel'ithl(' s ize and d i muing to l ht' l ret' tops. The last 
is, howeve l', usually of thl>. (')'et'pillg' [01'111, with the HUlin Sf·e m under­
ground. 'l'lw IWl'haccOUM 1Ilt'lIthel's of this association are, in the 
smaller groves, chieli)" plan Is ehal';wt (,I'is ti(~ of t he open Rtl'anU I Chloris 
JAn the specimeps of live oak seen were apparently of cOllsiderQble age. Seed­
lings were few or none, and no acorns were observed. It i~ probable that instead 
of increasing. the oak is here holding its ground with difficulty. So highly are the 
trees valued as wind·breaks by the inhabitants that none are felled, all fuel being 
brought from the mainland. The rounded shrubby form of this plant. common 
elsewhere on the coast. was not observetl on Ocracoke, 
272 THE PLANT COYl>l!lNG OF OCRACOKE ISLAND. 
petraea, Physalis viscosa, Diodia teres, etc., and the difference in soil 
and light is not sufficiently great to cause any apparent modification 
in the plants. In larger gl'oves, where the light) is more diffused and 
some humus collects, Oplismenlls setarius t covers the gl'ollud with its 
creeping stems, associated with such normally shade-loving species 
as Sanie"la sp., Asplenium platynew'on (.d. ebel/oides), Uniola laxa 
(U. gracilis), Panicunt laxiflorllrn and two mosses, gl'Owing 011 the 
ground, Bryum argellteurn and Rhynchostegium 8erl'uiatum. 
THICKET I.<'ORMATIOX • 
. 
Thickets of lIe.cI.'UlI!itoria, by far the most abundant woody pl •. nt 
of Ocracoke Island, often cove,· the low dunes, especially neal' the 
inner side of the island. The plants lire here usually 10 to 20 deci­
meters high, with short, rigid, thOI'll-like bl'ullches, light-gray bark, 
thick evergreen leaves lind hright sCIIl'let benies. The brallches are 
often shaggy with lichens, notably Ramalina rnontagne£. Occasion­
lilly the Hex gives plllce to slUall, dense thickets of j"Iyriea carolinen­
sis, sometimes 4i meters high. This formation corresponds ill a 
measure to the "Maquis" or "UalTigl1es" of t.he western )Ir:diter­
raneall region. 2 The herbaceolls species that have established them­
selveR among these shrubs are chiefly such as are most abundant on 
the beach and open dunes. Two thill-leaved, shade-loving herhs are 
occasional, Parietaria debilis with weak, much-branched stems, and 
Melolhria pendula, with twining stoms. 
SALT-MARSH VEGETATION. 
CREEK-MARSH FORMATIO:S. 
Salt marshes fringe all the small crooks and ditches that illterseet 
the lower part of the island, and sometimes covel' hroatiel' tracts imme­
diately bordering the sound with a gl'owth that is almost everywhere 
dense and reed-like. Two rather shal'ply defined he Its am (listin~nish­
able alung the larger creeks, an outer, covered chiefly with Spnt'fina 
stricta, and an inner, where Junclts roeme;-iwztls predominates. The 
latter alone occupics the small creeks and ditches which are farthest 
from the beach. 
til'ARTINA STRICTA ASSOCL\.TIOX. 
The Spal'tina prefel's the edge of open wat,(w, whel'e it, is in larg-e 
part Bubmerged at high tide. It has a light., yellow-gTeen colm' dur­
ing the growing season, but is hrown and discolored much of the year. 
The stems are usually about H decimeters high. Salico/'Hiu. herbacea, 
often lll'ight red and conspieuous, grows rather abundantly with the 
J In southern Mississippi. also, I found this specieg growing only in the shade of 
Quercll.'l t'iryiuiaJw. 
~ Compare Griseb&cb, Veg. der Erde, vol. I, pp. 21)4, ;j~tI, etc. 
• SALT-MARSH VEGETATIOX, 273 
grass,' Distichlis spicata. (D, nWl'iti11la) usually accompanies (.his 
association, but is not of primal'Y illlportnnce. 
JU~Ct;S ROEllERlA~t.:S A~SOCU.TlO:oJ. 
The Juncns roemel'innns association occupies much more ~onnd 
than that of Spartilla, atu.l c.:ompl'ises a much larger number of species. 
It is best developed on land that is merely wet a great part of the time, 
ana covered with, at most, oilly a. fow celltilll et~ I's of water a.t high 
tide. The Juncus is of a dal'k-gl'een color, and usually rcaches a. 
height of about 1 meter, HULking a dense gl'owlh of stiff, sharp­
pointeu stems and leaves. Amollg the ~ccondal'Y members of this 
association certain grass-like plants OCClll' locally in somo quantity. 
Notable are Chae/oohlaa imberbis peren!!;., with weak, slender culms 
from short, knotted rootstocks, preferring the bo,'ders of the marsh, 
and Typ/w latifolia, usually standing ill wate" of oome depth. S))(",, ­
tina patens (S, .ittncea) is occ>lsional, the Mlt-lUat'sh form being smaller 
and mOl'e slender than that which gl'OW~ upon the sand strand. Pa:;­
palu1n disiich-u1n and Distichlis spicata are also met with in more open 
places among the J UDCUS, 
Compositae, with mostly rather succulent leaves, are conspicnous, 
e~pecially neal' the margin of this association. Aster tennijoliu,s, a 
slender rush-like pereuuial species whose few branches terminate in 
solitary, rather large heads with showy white l'ays, is less abundant 
than tho related Aster subulaius, a. much-hra.nched, often rather stout 
annual with numerous inconspicllolls heads. Solidago sempervirtrts 
and Bacchar-is halbnifolict arc most at homo au tho edge of the Jutlcns 
growth. Both are showy plants, the latte,' with bright white papl'"s, 
I the forlller with a golden-yellow panicle. Bon'-ichia jtutescells, one of 
the most characteristic plants of the strand, prefers comparatively 
open spots where the ground is merely wet. It has it stout Mtelll, 
uSHally 3 to G decimeters high, thick whitish leaves, and yellow sun­
flowcr~likc heads. I vafru,teseens is tho most abundant composite of 
the marshes, allllost always a::;sociating with the Juncus. Two climb­
iug plaut.s, Galactin "t'v"uvilis (G. pilosa) and Vinceioxicum pcdusfi"c, 
a glabrous, ual'l'O\v-leavec1 ast:lepiad, occur Hell-r the c(lgcs of the marsh, 
twining ilrollnd the :-It-ems of the l'll::;hm~ and other plant::;. Atl'ill/ex 
has/uta is o('casional ill si milar sitllation:.;. Even Ile,J; I'Vinitoria :;ollle­
times tit,rays into the marsh, growillg lLlllOlIg the Juncu8 as a low 
stl'aggling sht'uh. 
Somewha.t differcnt is t,ho as.lI;jcmblag-o of spec ies abuut the :imAll 
p001s that frmll1cntly interrupt the gTowth of JIlIl(':U.~ l"tJeuwriH1tu.'). 
1 Likewise in southwestern France, S}J(U·ti1m .. "!l"rida and SaiicorJlia herlKtcea 
form the outermost Bsaociation in soil that is submerged at hi~h tide. (C'onte­
jean, (Jeogr. Bot., p. 56,) According to 'Varming (Lehruuch, p. 307) Salir.urnia 
herbacea grows unmixed with other specieg B'3 the outermost elllbryophylic vegeta­
tion on the eastern 8hore~ of the North Sea. ::;JXLI'tiua strictu does Dot range 80 
far north in Europe. 
200:> 2 
274 THE PI,ANT COVERING OF OCRACOKE ISLAND. 
Their bortlers at" \.Ite raYorite habitat of a characteristic malvaceolls 
plant, Ko .• lelelzkya "iJ'gillica, which hns ""tlte" thin, pnbt'llCent leayes 
and large rose-colored flowt.'l~. "~ith it grow n 8pceie~ of Rumex, 
Ipomoea sagittata, Solidntjo sempert'ireus, Gln.dinm e.tJ"sum (a stout 
sedge with sharply snw-ndged leaves), Po.nicum walieri, and, n~ry 
conspicnous where it 0('(1:\11':-0, Annrnpoaon g70meralus (...4.. 1wICrOUru.~). 
In tho shallow wat.('ol' of these pools gl'(}W~ )lfonniera ·mollnie.ra (lIe". 
pesti.q monn"iera H. R. K.) in its ltqllat.in, partia.lly sllbmergN\ form 
with elongated stem~, a~ Wt'll RS .AlIunannia koelmei, Pllichea ('(1111-
phorafa, and no Mpccies of EI("o(>hnl'is. 
DCKE-MARgH FOR1IATI()N . 
.A low, rn.t.llf'1' scanty YPgetn.tion CO\~l'J'S limited fl,l'PRS of wet. sana 
which fringe Ute )'('ell marsh, gpparating it from the dry r-.t.raml, nud 
also occurs h(>l't~ anll t.1WI''t' in depl'("ssion~ Hluong the dml('~_ The 
most charnetcri8t,ic sl-.ecieg m~ tilt' t(\lTt'sh-inl fOl'm of .:.lIoUllh?I"a. ""011-
n;erft with short intct'HOth .. 's, and Lippin uo<l'ijlora, both hnYing l"t'lwnt, 
8temg I'ooting at frequent illtel'nl1g and It''ayc~ mmally nppl'("sscd to 
the gronnd. In the (',ase of J.lippin, howeye l', 1.110 leaves a.rc sometimes 
nt~al'ly n.,'l'tical in Htl'Ollg sunlight, giving tht~ plant, a lx~culial' appeal' ­
al)('('. Eaph of tll('se ~lW('ip:-l :-OOIlWtiUWS OC'cnpieos small tT'acu; to the 
ex('lm~ion of other vegetat,ioll. TIlPY l1~l1al1r l!I'OW toget,her, hO\\'c\·er, 
awl in associntioll wit h H!lt7l'o('of !lIe -111111}ellafa, Cenlella (r,II;nl iea I and 
I>imlin -l'iJ"g-tIlWlut, nil smnll plunts wit h .('I't\(~l)illg or prostl'a.te Hh.'mg, 
Amollg tohc dillies J.ippin. ntHl ][Pl'lX'sti:-; ~onH't,imt's plny Il. 1p:-is impm'­
tant part, Rl1l1 an fl.s:-if!mblng<' of ~pp('il'~, ,,",Ollie of which al'O no t HOt'­
mally halophilous, C'o\'el'S tlw grotlnd_ Of the~c JnncliB di(:h(JfoHIIU;, 
J. sch'poidf'S, ScirlHt.'HUlwricanus (8. pnlluen8). Tl'iglochin.'ifr-iatu, Hna 
Mikania R('(mdeu8 an' lHOl'C at hOllle in :-iHliliC soils, whilo JJlldu,igia 
'mil'J"fK.'fII'lJrt. L. nll/to, CYllocfo llwn 1Hitl'eolu C~fitre()ln pel/ohlin) , awl 
Dif·!t,'mnenlt ('olm'fflll (/). lelll'o('epliala) a 1'(' ('haJ'a('t-el' pllLHt.s of Ill(' 
f.'cHh-wafm' IIHlI'Shcs of Ihe I'('ginn, Such ('oulIllingling i:-; pm'hUI):-i t·n 
he e.xpla,jll(·(l hy t.ltU fnct, tha.t; t,hese hollnw~ among Ule dUlu's t.lpl'in' 
theil' moistul'e l;lI'gely fro III flit.' rainfall, whilt\, Oil t.lll' otlH'1' hilmI, 
spl'ny-l:Ltll'n wind~ ("ollt,I'ilmtt' a. 1'(,l'tain H-Illount, of salt to 1-h(' soil. 
TIllAr.. FLAT FOIOl;\TloX. 
Thi~ is an open fOI'maHon, oCC'llpying 1.1w margins of tlw shallow 
lagoHIl at 1 he )m\"l'" t\ lIti ,)f t hp islnlHl, whi('h is Hlulc.· wat.tll· nt, flood 
tid." . TIlt' soil is a. JIIixtUI't' of siJt, filul :-iand. ...\ spat'S(' gl'owtll of 
SNHI1'ill111- 11wyililllwn (S. lU)lIlalldl'lI1l1). '1'i,-:; .... '1 1lHlriulI- (L(-'piUOlW11I 
,wtii}//())/), tl.11.1 S('irpll."i (luwri('(/II/{s fOl'lIl s II e hanwtpl'i!o'ti(' n~so~iHtioll. 
PasJlolu1n distit'7/1/1II, with PI'ost.l'at(' ('nlll1~ , sometinlf's ~ lIH't.ors long, 
rooting- at, the llO(lps, as WE' ll ns ~caU.PI'l'«1l' l'('d, t.ufts of FiJllb,.i:~f!Jlis 
spar1iep", W(\)'P th(' emIr o1her sppcies ohsern'(l in thi:-o fOl'lIllltioll. 
• 
• 
ECOLOGICAL FORMS. 275 
PASTORE AND RUDERAJ. PLAN'l'8. 
A ~()nsider"ble al'ea towards I he lo\\'er end of OCI'lWOke, especially 
in·H.H<lneat' t he village, is eovered wi t h a fino turf compo8ed a.lmost. 
enti rely of Capriola dacty/oII, closely grazed by horses, cattle, Itlld 
she~p. Here and there over these pastures are scattered groups of 
Vltri01lS weeds, notably Cu"s'ia occidental-is, Sporobolus indicu •• and 
Solanum carolinense, as well ItS a species of Xanfhium, Bideus bipin­
nata, Ghe,wpodium antheirniniic""" Ambrosia artimi..iaefolia, r el'­
ba.cum lhapstl., etc., all of which 11I\\'e 1lndonbtedly been import~d 
inlo I,he islaml by the agency of man. Occllsionally, 81mys from the 
indigenous formations are lIlet with here. 11~leshy fungi are sparingly 
represented. 
Cl1LTIV ATED PLANTS. 
A~ fn.r as was ascertaineu, the only plants 11lH"- cultivatetlupon the 
island are fig trees (Ficus carica), which are planted about dwelliugs 
and freely mature their fl'tlit in this lIIil<l c limllte. Small pIlper mnl­
belT)' trees (Brousso"eti" papyrife·m) aro established in <loor yards . 
According to a statement above quoted , peach trees and potatoes were 
formerly grown. Attempts tu <'ultiYate garden vegetables are llsually 
terminated by inroads of the sea during a. gale, which leave tho soil 
strongly impregnated with .ltlt. 
ECOLOGICAL FORMS AIIIDADAPTATIOlll8 TO EN VIRONllElfT. 
III (·onsidering the physical environment of plants upon Ocracoke 
Islan(l, a.Jul the variolls modifications of tho vegetative organs wh€'re lJr 
they " re adapted to t.heir medium, it is e"iden t U",t many of tho la( \<.1' 
full readily into two categories: (1) Adaptations }ll'ot.-'cting agai n~l t ht:' 
ntl?!chanical action of the wind 1 and the ullstable nature of the suil; 
awl (2) modificaUons that assist the plant to inCl't~H8e 01' conser\'e its 
supply of water. Santl·strand and salt-1IlIu'sh species alike reqnil'e 
bot,h sorts of modifications, although Ute lutte l' formation is Il'ss 
exposetl to willd and the shifting of its substl'at um. Howel'er, lIot 
ouly the vegetation upollloose sand, but that which co\'ers the muddy 
boltom of the salt ma.rshes, must accommodat. t.l it~elf to a. more or less 
incoherent and mobile soil. To the first cat.egory are to he referred 
mo~t, of the notewort.hy life forms of the i:-;huHl, i. (", those in witieh 
the ppharmonic peculiarities of stnwtul'e (sn ch as arc dne to tlH' 
tlireet, lI,ction of the physical environment,) extelld to the entire Ol'g'Cln ­
is m, To the second belong chieHy modifications of a pal"lieular Ol'g-all , 
t he leaf. 
_. -- - --- -- ---- ---
1 The exposed position of the island, and its consequent relative po\'erty in large 
woody growth, renders herbaceous vegetation he~ wore than usually subject to 
the action of the wind. 
276 THE PLANT COVERING OF OCRACOKE ISLAND. 
ADAPTATIONS TO 'l'HE MECHANICAL ACTION OF THE WIND AND 
THE INSTABILI'l'Y OF TB FI SOIL. 
A notable characteristic of the vegetation is the prevalence of low 
forms. Tall stems (more than 1 meter high) among' herbaceous specieN 
which are not grass-like, are almost want.ing. Often the stems Cl'el'll 
above or lwlow the surface of the ground 'Ind J'oot at, intel'Yals. 
Lippia nodifiora, JIonniera monniera, Capriola dactyloll, and Pos­
pabon disUc}Hon have stems creeping npon the surface. These TIlay 
be regard~d as humble representatives of the Pes-caprae form, whi('h 
is so characteristic of tropical strands. 1 Species possessing creeping 
subterranean stems, from which arise subaerial leafy and fioweripg 
branehes, arc Panicllm amco'1Im minus and Un-lola pnniculaia., as well 
8S many of the salt-mal'sh plants, notably Junells "oemerwn,,", Typ/w 
latifolia, and Spartinrt. strida, whose strong, creeping rhizomes form a 
dense sod in the loose mud. In Uniola panieulala the root,t()ck is stOllt, 
and descends obliqllely 01' almost Yertically deep into the sand. 
Physalis 1·iscosa has a long, sleuder, branching root, which (,I'eeps 
horizontally often a distance of a meter or mOrC ncar the surface, and 
originates at intervals erect, leafy and flowering branches. Teucrium. 
nash-ii possesses thickish stolons, which arise in the axils of the scale­
like, lowest leaves. 
Other species growing on the salHls have prostrate st.em. branches, 
which do not root aft.er leaving the main axis. Thes(' Illay be long aJHl 
trailing, as ill the woody Rubus trill/ali..;;, or short and radiating in nil 
directions from the primary axis as in certain annnals, Diodia. teres, D, 
1,irgininnn, J.llollu!}o verticillnia, and Euphorbia 110/Y!101ujoZia, as W4'11 
as t.he bif'nnial Oenot}u'rn 7l11mifusa. This radia.nt form,2 as we may 
term it, is not so abundant and characteristic here as at other point s 
along thc Atlantic coast of the United States. 
T!", c~spitose form is apparently not well adapted (,0 conditio", 
npon O('l'aeoke, for it is well developed only in .. lfllhlen7)eryiajl/ipl-'.". 
The slll'uhs and trees of the island show the effect of lHlleh ('xpOSlll'e 
to high wind in their short gnarled branches and in nw oft.en 0114'­
sided posit.ion of their crOWIl of foliagoe, the last, pecnliarit,y lwing' 
espeeially noticeahle in the live oak. Here, howevt'l', wo ha.ve to do 
l'athf'1" with the (lirect mechanical effect of t,he wind t.han with a pro­
t.ectivI' mo<lifi('a.tioll . 
.As f'llrthpl" lulapt.ations against the coast winds, whose destrnctiYe­
ness to t.end('l' vPg'ctatioll must be greatly increasell by the quantity 
of sand they carry, should be cited the great den"lopment. of mechan­
ical tissue in the leaves of many species-(\, g., Uniola. panicu/atu, 
JUHCliS roemeriwlIls, Quercus t'ir!liniana~alld the strong t.hickpning' 
. . 
of the outer eell walls of t.he ephlt~l'mis, to which is due the hard pol-
_. _._- ~-------
I Schimper, Indo·Mal. Strand· flora. p. 7i:l. 
~ Schimpur (8trand-flora, p. 81 ) describes this form as occurriug in the .1£ast Indian 
strand vegetation. 
COLLECTION AND STORAGE OF WATER, 2i7 
ished ~nrf"ce cl<hibited b)' the larger grass-like plants and by the 
evergn,-c ll. leaves of Que rcus a.nd flex. This last pecnliarity is, how­
e\'e l' , doubtless primarily induced b)- the n~cessity for protection 
against loss of water. 
ADAPTATIONS FOR PROTECTING THE SUPPLY OF WATER. 
:;tl'and plants upon Ocracoke Ishlrud, unliko desert. pia,nts, are not to 
allY notoworthyextent. eq uipped withspecia.l A.ppal'atud for collecting: Ol' 
foJ' storing water, if we except tho developnwut of water-storago tissue 
in sevel'alof the saU-nHl.rsh species. The ullvions reason is tl1e a.bsence 
of a pel'ioc! of drought, th ere being' at all times a relatively high per­
C(\lltng-e of ,vater in the ail' allll the soil. 011 the othor hand I botu 
lll;tl'itirnc and desert vegetatiolls arc characterized by certain pecul. 
ial'iti(' ~ of structure, especially of the lt~aves, which a.re usually 
dt>llominat.ed xeroph~rtic, a ll)(·it these a·l'O k-ss strikingly ueyelopt-ct in 
straud plants than in tho~e which inhabit deserts. Such common 
points of resemblance are , as is well known, tlue to Il, common n ecessity 
for protect.iolL against excessi \'o loss of wa.ter by transpirat.ion from 
the Ie-liNes, and this despite the abundant supply of waleI' in the 
e nvironment of straml plants, 
In tho case of salt-marRh vegetation it is chit!fly tho preseuceof a com­
pUl'atively high perce ntage of sodium ehlorid in the soil watel' which 
n ecessitatt.·s a xerophytic struchll·c. Just how this salt reacts upon 
the life pl'oce.ses of plants and what t he precise mode is by which 
plants protect themsel\'es a.gaiust its injurious effects are mnch mooted 
qncstions. l 
... _- _ ._._._- - - ----- - - _ ..... _-
1 Contejean (Geogr. bot., pp. 71,94) holds that salt is harmful to most plants: that 
it is not indispensable even to strand plants, and that the latter are confined to an 
othel'wiliie unfavorable habitat m erely by their inability t o compete in the struggle 
for e xistence with the salt-shunning species of llonsaline Boils. That this view is 
only partially correct is suggested by the known tendency of halophilous (salt ­
loving) species to take up greater quantities of sodinm cblorid, e\'("o when grown 
in nonsaline soils, than do plants ~bich are not halophilous. 
Schimper (Strand-flora, pr. 2; . 2!i) att ributes to the accumulatiou of sodium chlo­
rirl in the green tissue an injurious offect upon assimila.tion, particularly upon the 
prorluction of starch aOlI sllgar. More recently (Pf1auzengeogr., p. 10C) h (> modi ­
fies this view, but still emphasizes tilt) importance of a chemical action of the salt 
upon metabolism, the synthesis of proteiils being the process chiefly affected. 
In ord(>r to reduce thi:'J deleterious action to a minimulll . the accumula.tion of 
eodium cbloritl in the tissuf'e must be as far as IlOHsilJle r~ta rdt>(l. This is nccom­
plished, according to Schimt>er'li theory, by (liminishing r ont o:"mosil; and hence 
the "olume of the ascending column of water holding thf-' ch~ori!l in solution, 
this end being secured by means of certain modifications of Jeaf structure that 
r educe the volume of transpired water. Besides this chemical effect, Schimper 
also a.dmits a direct physioal iufluence whioh the presence of common salt in the 
soil exerts upon the proce88 of 08111osi~, As Sachs (Landw. Versucbsst. vo1. I, p. 
223) demonstrated by experiment, the roots of ordinary plants take up with diffi­
culty water which holds in solution sodium chloricl I as well as other salts . nota­
bly calcium sulphate) , a difticulty that of course increases with the concentration 
2 i 8 TilE PLAN'!' COVERING OF OCRACOKE I~LAND. 
}'actol'S ill the physical environment of sa.nd-strand vegetation 
which tend to accelerate transpiration from the surface of the plaut, 
and hence contribute to the necessity for xerophytic structure, an': 
1. Exposure without shelter to the almost contiuual and often vio­
lent movement of ail' currents, which keep the plant's atmosplwl'ie 
envelope ('ollstantly changing and preV('llt it from approaching a CUll­
ditioll of saturation. 
=? Intense light, both dil'eet awl reflected from the snl'faee of the 
sault Light, which becomes couverted into heat ill the dllol'ophyll 
tissue, increases transpiration 1 in propol't.ion to its intensity. Besillcs 
this ciTed of light, its direct and harmful action, when t.oo illtenst.~, 
upon the chlorophyll is to he guarded against, and this is prohahly 
effected by some of thc modifications which also sen'c to redu('e 
transpiration. But in the present state of our knowletlgc it is impos­
sible to lliscriminate between the respective lllOtlitil.'ations whieh 
protect the plant against these two effects of light. 
il. Great heat during a great part of the year. :Much morc illtenbt~ 
than the atmospheric heat is that which is absorbed by and reflected 
fl'OIll the superficial layer of saud. 2 
It is probable, however, that the presence of a high percentage of 
sodiuIll chloricl in the substratulIl is at least as effective as any of 
these causes iu bringing about xerophytic structure. This is evident 
-- ------------ - - ----
of the solution. Whether this is equally true of halophilous species is not 
estabJ ished. 
L. Diels (Jahrh. Wist;. Bot. yo1. 23, p. 316) doubts that o!'.mo:-is in pla.nts of saline 
smls is ~ufJleiently reduced to account for the nbsence of accumulp.tions of salt to 
an injurious extent in the tissues. He found that salt-marsh plants when trans­
ferred to distilled water showed a steady loss of salt from day to day, although the 
impossibility of an excretion ot the sodiulll chlorid as such could be demonstrated. 
This author gives a number of analyses of halophilous species which would indi­
cate that in plants of that character the cells are enabled to decompose the 
accumuht.tecl sodium chlorid, the sodium pr(Joobly uniting with malic acid, while 
the chlorin possibly combines with water and passes off through the roots as 
hydrochloric acid. It is known that xerophytic modifications whir.h protect the 
plant against excessi .... e transpiration at the same time cause an increased evolu· 
tion of tree adds (notably malic acid) in the green tissue, by preventing the 
ready access of oxygen and otherwise hindering the exchange of gases between 
the plant and the atmosphere. Thesll researches of Diels. if confirmetl for halo­
philous plants generally. will prove an insuperable objection to Schimper's theory 
that such plants can prevent an indefinite accumulation of sodium (~h10rid in 
their tissues only by reducing root action and hence transpiration. If we accept 
Diels·s conclusions. we should have to refer the xerophytic structure of halophilous 
plants largely to it!'! efficacy iu preventing a. fr&' exchange of gases between 11lant 
and atmosphere, thus rendering imperfect the combustion of carbohydrates in the 
plant tissues and occasIOning the production of considerable (luanti tieli of organic 
acids. which serve the pla.nt hy decomposing the absorbed sodium chlorid. 
I Wiesner. Untersuch., p. aOli. 
~ Volkenli (Fl • ..;Egypt" p. 14) found adifference of from 22" to 24° C. between the 
temperatures of the surface soil and of the atmosphere in the shade near Cairo, in 
Egypt. the maximum heat ot the sand being 55° C. 
MEANS OF REDUCING 'l'RANSPIRATION. :179 
when we examillu thQ :-mlt-ma.rsh vegetation. )lost of the species of 
that fOl'lllntiull, even those whidl a.I'C wholly 01' pa.rtia.lly submel'ged 
at high tide, possess sHch structure. Xu plants of the XOl'th Carulina 
stl'anc..l arc more conspicliously xerophyt.ic in structure tha.n BoZicornia 
lwrb{lCc((' and Spal'till(l. strieiu, That such structure is closely rolated 
10 the abiJit,y to take up NaCl ill consitlemblo 'Jnantities is pJ"oycd by 
the f<let that certain speeies which do not lUttllrn.lly inhabi t saline 
• soils, but which possess stl'ollgly tll'yclopetl modifications Hg"ainst 
excessive transpiration, Can ahsm'h t.hat. snIt in (jlUUltities that are 
fatal to plauts not 80 cOll"titutetl.' 
For t·his l'C'ason species lwiongillg' l'espN!tively to the sanu strand 
nud to the salt marsh of Ocracokt' Island al'c not distinguished in the 
foll owi ng enumeration of t.he meClll:s I,y which t ranspiraLioli is red uc.·ed. 
1. Reuuction of the transpiring snrf!we. 
(a) Leayes small: Ilcx 1'O'mituI'iff (tJlllallest-leflvell of our species of llex ) , aulae­
t ia ·t '(llnbili.~ (unusually narrow-Ieayed form). l"in('doxicum palusln'. Tis.<;a maril/a 
(lea yes hemicylindrical). .1/01111 ict'(( mUll II jail, Lippia I/oo{tforu (lea ves no ta bty 
smaller than in nonsaline soils). Se.·ml'i1l1lt 11110' '-1;/1111111. t'tc. Most of tbe species 
enumerated have small or narrow leaves as compared with the nearest related. 
inland forms. 
(II) Leaves scale-like, their fuudiollS transfel1'ell to the stem, which is succu­
leut; stem succulents! OjJulltiff jlC,'N.'O/Ti, Salicul'lIia /iel"imcea. 
(c) Leavp.s conduplicate or involnte, especially in dry, sunny weather , so that 
only the dorsal surface is expo:;etl: All the grasses, and Gladi-um e.t!u8um, Pim· 
bristyli.'f I'Jlwii('OO, and other sed~es, In tht) I{rasse8 this characteristic is corre· 
lated with th(' position of the stolUnta, which lie at the bottom of furrows, e81)6-
c1a11yon the unexposell ventral surface. and are further protected from air currents 
by a network of hairs which line the walls. In QIlt:I'CU;:t "l'iryini(llw the leaf war· 
gins frequently become more or less revolute. 
(d) Leaves perfectly tereta and in structure little differentiated frOlu the stem: 
JWU!U:l ruemcrianwf. 
2. Position of the transpiring surface, leayes vertical or nearly so: Many of the 
~ra8!5es and sedges, 7'ypha, ,j/l.//(' Wf ,·(wIIWl"illllll.'I , '/'1"I·yluddll striata, young leaves 
of l ~t«..'('a 8pp., Lippia nodijlolu (sometimes), l·inccio.t'icmIL :JXIl"/li~tl'c (leaves 
reftoxed), the Cornpositae. 
3. Development of protective 1lIU\1ification s in the ephlenuis. 
{If) Thickened cuticle: )fallY species, notahly the larger grass-like Illants and 
woody species with e\"ergr~1l leaves. .-\.. shining upper leaf surface, as in Ilex 
1:umitori(/, IllSY be of use by reflecting some of the incid.ent light rays. as has !Jeen 
suggested hy \Viesner, 
(II ) Waxy covering: j ·'mdclUlL fUm/rUlli, [~lIiola. JJHI/iclllata, };/Iplwrf' iu j"lflly· 
gUlli/ulia, etc. This chal'acter is but slightly J.e,oeloped in the vegetation of Ocra­
coke Island. 
(c) Hairy covering: Oeuolhcr(f IWllli/usa and l~ ' I/('r ilill/. IIoNlIii ( hair~ lunS, 
simple); Qlu~rcw1 t: irgiltiall<t (stellate hnirzs on the tlorsnl surfa<."e only); Koxl elelz­
kyo 11irgin-iea and CrotolL 1Iw-riti1ll1l.t( (hairs ste1:&te. scale·like); Phy,<w!is t.~i.'icm.a 
(hairs forked); Borrichiajrll tcscttUS (youu~ leaves very densely covered with short 
bail'S, giving the surface 8 glistening appearance) . Interesting hairs also occur 
ou other species, but not in sufficient numbel'~ to serye as a protective covering 
(except in the leaf furrows or certain Gramilleae), 
• " ..... _ - ----- -
, Schim per, Pt!allzengei>b'T" II. on. 
. ' 
280 THE PLANT COVERING OF OCRACOKE ISLAND . 
• 
4. Succnlency. 
«(I) Stem succulents: Op1!ntia pe8,cO/'ri, Salicm'nia herlwcea. 
(11) Leaf succulents: rlf('C'a spp., Tbum mar-illn, Se.'JlwiIl1ll maritimmn, EupliOr· 
bia polygonifolia, Villceto,t';('I(1/t paillstJ'e, Aster sl/lmlatus. A.fle,"Ito.'wR, Solidago 
RelllperI'irelIR-moetly salt-marsh ~peciM. Not only does the increase in thickness 
of the leaf serve directly as a l)l'otectioD against excessive 1068 ot water, hut the 
thickening tissue consists, in most cases, of colorless, water-storage parenchyma, 
which is peculiarly tenacious of jt~ \valer snpply. 
n. Structure of the chlorenchyma. 
Nearly all the species, of both sand strand nnd salt marsh. are cha.racterized hy 
the den'llopment of palisade, a compact chlllrollhyll tissue with cells more or less 
elongs.te<l at a right ang!e to the surface nnu OCc.~ullying the exposed facf' or faces­
i. e., the ventral ftLce in bifacial leaves, hoth faces in Roeh as are isolAtera1. Snch 
tissue is be!ieveU to have. among other functions, that of protecting again~t ex· 
ces~iye loss of water the remainder of tho leaf (the interior. or the lower face, 38 
the case may be), which il'll1suany occupied by less compact tit:sue. 
B. Aromatic, volatile oil. 
All oil of this charncter is secreted by the species of Myrica. It has been 8Ug· 
gestetl. although the idea needs substantiatioll , that the po$89Ssion of Buch oils 
affords llroteetion againsii excessive 1()8s of water by the formation about the plant 
of an envelope, which is less p ...:rviou8 to heat rays than is ordinary air. At aoy 
rate this is a frequent attribute of plants inhabiting very dry regions. l 
~ot to he int.t·l'pret.c(l a~ affording pl'otection Against (>xcossiYe 
tm.Hspil'ation, yet pPl'hnps hu'gt·ly tlllf' to Ow influent't' of conditions 
that lle('P:ssi t atn 81U'11 protect.ion, is thu cltwt'lopmellt of shol't, rigid, 
n1l110s1, thorn Ii ku branche~ (lh:.r. rom itoria) and of prickles and f'pincs 
(Smilax, RltlJll.~ trivialis, Opnntia, ZanthoxylulII, ]C'af apices of the 
sllOCieR of YUC(,H). PI"oha.hly Uw tlepal1}X~l'ato form assumed by AOIllC 
of the wootly spC'cies whell gl'o\\'in~ on tht\ h('af'h is similarly explicable. ~ 
Strong thickening of the 1Illtler-gl'ontH11'arts for storngp of l'eselTe 
foot! lllaterialli uoes Hot OCCtll' ill many Hpccies. The only notahle 
cast's clet('cted wero SUlilax 1uma-}/o.)' (I'ootstocks with tuberous thi('k­
eninlrS), Yucca "JlJI. (motstockR large, fleshy), and Koslelelzkyo ,-il'­
ginic(f. (ront stout, w()(Xly, YCI·tical), 
ANATOMY. 
In almost all caRCS thp histological !:'Ll'lWt.U1'C of t]l(' leaf alone is 
hel'o con~ider(\(l! tllnt. ht.~illg' Ute organ whi('h shows most pla.inly 
I\anptation~ 1.0 ct'rtaiH fa.ct.oho: of Ute t.\llvit'ollmcnt" nota.bly f.hose 
whidt a,ffert. t I'IlHspirllt iou. The gt'm')'a \ peculiarities of leaf auntomy 
in t.he Yt'g('tal ion of the salul Mt rantl and lIf the salt marsh, l'{-,sl)(\e~ 
ti\'(~ly, arc first, N1111llt'rnh\d, allcl Ow l'(-'st.\lIIhlau(ws antI uifferencP8 of 
plallts of tho two formation clnsst'M arC' poillte,t! out·. Severnlof the 
1001'4.' impol'tiUlt 8pe(·it'~ of (meh (';It.'gury, in all 1hir1y-two, am t.hen 
I Haberlandt, Pflanzenanat" p. 325. Vol kens, Fl. )Egypt., p. 46. 
~A like depressed habit is chaTactelistic of shrubs growing above the limit of 
tre(;s in high latitudes and altitudes. It is usually fl.ttributed to e:tposuro to strong. 
dry winds, whieh is probablr the chief factor in its development 011 the beach ot 
Ocracoke Island. 
• 
PROVISIONS FOR CONSERVING WATER. 281 
taken up anu de!SCl'ibeu in systematic order. Ta,bIes showing' what 
are believed te) be the ch<tl'actcl's that, are most important from all 
ecological point of view ]mve been prepal'ed feB' tho two groups of 
species. For A. number (If S}weil'S t,he ' material studied was not 
ohtnined npon Ocracoke ] :.; lnnd, hilt f l'olll s imilar l5 ituations on the 
{'oast of Virginia, and in aU HllCh ca.~es the source of the specimens 
u sed is mentioned. In Homo eases COlIlllCtl'isons are made with related 
species, usually from otlw l' formations, in order t o make clear the 
differential characters of the strand :-Ol)l,'cief.;. 
In a great majority of the sand s(mlld pla.llts 1 he leaf is bifacia.l, 
t he two species of YUC("t. IH'ing the only cx:copticms Hoted. III some 
species this specialization is imperfect, as ill Geno/hera· hwwifusa. In 
other cases the differentiation of th e 1'1'0 sides of the leaf is CODl­
plete, as ill Quercus 'l)iryill irUI(I , In most cases the leaf hi thick as 
compared with the same or~nll illl'clat.(!'tl UOlluu\l'itime spccies. Good 
examples nrc the cvergl'enu, leather'y INl\'CS Hf Qlle-rclI,s 1.'irginiana 
nnd Ile.-.c 'vo-mitoria , as well as the leaves of the two grasses, Clliola 
lJaniculata and PaniclUn wnw'wlt. A st rongly thickcnc(l cuticle is 
an almost iunLl'iable ehal'a.etel' , and this is conspicllously wrillkleu in 
a few species. The 1atel'al walls of tlte epidermis cells are undulate 
in fouL' species, viz, the ('omparat.i\'ely thill-leaved Chloris petraea, 
Teucriuln nashii, and Phy:.;{(/is "l·iscmJu, aull the thick-1eavcu Ilex 
vomiloria. 
Half of the species h,,,"e stomata on both leaf surfaces, but in every 
such case they are especially prorec(cd-in the grasses by being sit ­
uated in furrows; in tho species of Yucca. by be ing deeply sunken, 
and in Physalis, Oenothel'A., and Croton by a covering of hairs. In 
the woody species they arc always on the uorsal or lower surface only, 
and. in Quercus 'drginialla they m"(~ furth er protected by a hairy CO\' .. 
ering (as also in the herbaceous 1'e u('~ ' ilt1n 1wshii ). 
Hairs form a. dcn~e, Pl'owcth 'c covcl'ing Oil buth leAf s l1l'faces of 
Ocnothel'n, Croton, and I)hysalh:, wh ich species 11H\'C s tomata on both 
8urfu('('s: only 011 the (lm'sa l slll'fiH'e in QUC'l'CtlS awl T e ncl'ium, agree­
ing with th e positioll of the stomata OIl that surfatc OBI.", In Quercns 
and Croton tlw hail'S arc plul'i ct'llular atul stellate; in Physalis they 
nre it'l'egularly bl'fl-lIehpu ; in Oenothcl'a and Tl.'UC1'inm they arc t\lou· 
gHte~l, ullbl'a n clw<l , amI tlllic~llular. Te um'iulIl also posses.."i('s shol't., 
glahllular, capitat.e hairs. 
The chlorophyll tissue is homogencolls in the monocotyledons of 
the sand strand, while in t.he dieolylcllou s it is 11101'0 or le~s differCIl­
tiared into palisade on the ventral ,ide of the leaf /Iud pncllml\lie 
ti!;Sue on the dorsn.I side. The pali~a(h.\ is mostly lluit.e compact, but 
ney(.ll' of more t han 3 nlHl llsually of only 1. or :? layer'S. 
Colorless parenchyma, whidt prohably perform:; the function of 
watN'-storage tissue, occurs in cOll~illeral>le quantity only in t.he 
grasses and the speeies of Yucca. 
2112 THE PLANT COVERING OF OCRACOKE ISLAlm. 
~tereomo occurs slIbepidermally (especially ill the l~af margins) in 
the Gramineae only. In most of t.he species of the saud stra.nd, how~ 
ever, it is fount! as a support to tho mestomo bundles. These are 
furthermol'e reinforced by hypodel'ma.! collencllyuHl. 01' collcne1lymatic 
tissue in most of Ule dicotyledonous species, Ulis tissue }ll'obably 8 .. '1"\' ­
ing as a protection against loss of wawl' by entpOratioll from the 
vessels. 
The sand-strawl grilsses deserve further lllention with l'cfcl'(>nc{~ to 
their leaf structul'e. It belong's to a typo of which Chloris peirflea 
exhibits one extreme and J£1l7llenbagia jilil'es the other-the type 
exhibited by most gl'RsscS of d.eserts and. stepp<·s. The salt marsh 
Sparlina, striL'u£ exhibits n. wholly similar arrangement of tissues. 
The margins are morc Ol' less conduplieate or ill\'olut.c when the 
supply of wat,er is sma.lI, becoming flat when moisttll'e is plentiful, 
except in the lea.f of 11Ilthlenberyi-ttfilipes, which iscolldul)licatc, with­
out power to unfold, and ltPPCRl'S as if tert~te, The l"(~snlt uf lhis 
tulaptRtion is that in dry, sunny weat.her only the dOl'salleaf sUl'face 
is directly exposed to tho ail' and light, In Panicllm OUWl'um· and 
Chloris p etraea the moycmentis cffecte41 by truc bnllifol'Hl eells, while 
ill the other grasses (except, of course, l\I11hiellbel'gia) the function is 
probably performed by COl't..'till Im'go but oUlOl'wiso undifferentiated 
cells of the epidermis, which may be regal'ued a.,,,! undeveloped bulli ­
form ceUs, 
The stomata lie neal' tho hott,om oC deep longit.udinal fUlTOW8 and 
usually oC·CUI' morc ahl1lu.1antly Oil t.he )u·otected vcnt.I'ut surface of the 
leaf, but in Chloris petraea only on the dorsal sUI'face. The walls of 
these furrows, illl\lnhlen bergin, F niola, and Spa rtil/a lKltens, are Ii Jled 
with unicellular, simple, prickle-like hairs, whieh doubtless hinder the 
escape of moist air. 
Sube.pitlel'mnl gl'oups of stel'como OCc ur ill tho leaves of all the 
grasses I\nd in Uw margins of all except t.he )[uhlenberghl.. III this 
great development of strengthening Hssne we haye in all probability R. 
protection against t.he mechanical effects of the wind, to which stl'RUd 
grasses afO mnch exposed, 
The chlorophyll tis.."ue is in eyory case radially ul'rnnged in single 
layers al'oum.l 01' at each side of ca.ch mcstome lmlldle, In most, ('ases 
"ht.., adjaeent cplls of Ute parenchyma sheath also eOllta.in ehlol'ophyll, 
Each mestomc bUlHllll is 8l11'rounded 1Iv It mestome sheath ill an the 
-
species ex(':ept UJ/ioZa fmcl .... ~Illhlenbel'yi(l, aJl(I this hya large-celleel 
parenchyma sheath. The pfl,l'enchymn. sheath without thc mestomo 
aht'fl.th occurs in. J[,~hlellbe"uio, 
Among' the species of tho salt marsh which wero examined, t.ho 
isolRteral typo of leaf prevails, Kosleletzkya, 1.:iryinica and L(ppia 
11odifiom being the only exceptions, "nd in th~se the leaves are but 
imperfectly bifacial. Tn JHllCIIS l'oe1llCriaUlt8 the leaf is teret·e. 
Thick leaves are also the rule in t.his formation class, although less 
'l'IS~uES. 283 
strikingly so than in the sand 8trall,l, hecallse of the lack of large 
woo<ly plants; and the thickened leaf is IIslIa lly of a soft, RIIC('lilent 
character rather than leathe ry. .A majority of the species !-Ihow a 
con~picuou~ly thickenca cutie'Ie, whi('h is strongly wrinkled ill 7 out 
of 15 of them and granular or warty in 3 more. 
Corresponding to the isolatel'al st,)'udul'e ( )f lIlost of the lean-s we 
fitHl stomata on both E1ul'faees ill 12 spf'cies; 011 the ' ... ·bole eil'cumfer· 
ence of t.he tel'ete leH f of .JUIICIIS roemerimws.; f'onfint"d to the yentl'Hl 
or upper surface only in Spn i'til/ a ::.-1 J'iefa antl Borrichia jl'lde8Cfl.I1:3. 
In -1 species the gnard ('ells are slightly prominent, in 7levcl ,,,itl1 the 
.e-pidermis, in 3 slightly sllllkcn, ill 1 (Slxfriin(t, x/ric/a) situated nell .. 
the bottom of deep ful'l'ow:-(, Hail's oc(~ur ill hut 5 species, In Bor· 
richia alone they form a d{'lIse covering, nearly eve)'y epidermal cell 
appenring to ]lave tlew'lope(l a pluricpllulnr, thin·walled hair by 
tangential division, It is eyidellt t ha t wo have in this case an ad mi· 
rnule protection against excl':-3sive tl"llllRpiration. 
Ste-reome occurs in lIotahle qnant ity uuly in the len.n~s of 8.i.J(lrtina 
strirta and Juncwl 1'oemeriwlII ,"l , III lKith i t is subepitlermal HS well 
as about th e mestomo hun cHes, J,II/CIIS '~'oenu'riwltts is espe(~ially 
noteworthy for the strong (lcn~lopnwnt of both peripheral and axial 
stel'eome groups, lIypod(')'mal collenchyma , til' ('.ollenchYllla·like 
tissue, occurs opposite 1he vcius in two- thirds of the species exalllined. 
The chlol'cnchyma is hOlll ogeneoll~ in all bnt :! species, and in 1 of 
th{'se, Lippia, ll.odijiol'a, t,ILe diffcl'c llliation is s light. In nearly all 
the ~pecies it consists of compact palisade, interrupted in scyeral 
CR8es hy du~ts or lacunes, .Ill the. leaves of most of the species th ere 
are only 2: layers on etwh side of 1hc isolateJ'ul leaf, but in Junl'llS 
roemerianlls t.he bands of wen.dc\·cluped palisade a re £) or G layers 
thick. In severalofthl' COlllpositae, allllecirledly halophilous species, 
the ends of the pa lisade layers wh('ro they n but upon the midyein 
converge toward the vein and appeal' as if radiating from it, This 
was obser\'ed in I t'a ff'ldf'8Ce ll,~, Bacchal'is 7wlhmfolia, and Aster 
tenuifulius, and may OCCllr ill o lltel' species. The significanco of tbis 
arrangement is not. known, It is ('itc(I by 'Varming 1 as a halophytic 
chal'acte l'. Spw·ti/l f/. slridn agl'c(·,., in the arrangement of its chlo· 
JophyJl tis!')lIc.' , as in othcl' 1'('Spects, with the SHollt.1-St.I'HlUl gl'a:-;l'ie~, 
Colorless-lICll'enchyma, wltieh lll'oba.bly sCI'n's fot' the :-Itm'age of 
wate l" is 1)l'(\8('nt ill UTeate]' 01' less (Illflntitv in ~ SI)C!cies OCenl)\'iu(f , ~ ~ ,. ~
t,be greatel' pa.rt of the interior of t he leaf in 4, while occurring only 
about the veins in tho others, In Horrichia, wllieh is one of the most 
xerophytic ill strnctm'e of aU the 8Hlt·mal'sh species, this tissue is 
best developed, It is also well (~xelilplified in Ti<;SH marina. 
In the 3 satt ... mar.;l.h inhaiJiting monocotyledolls examilled-1:"iylo. 
--chin siriat.a, Spartina. siricia, (lwZ Juncus 'l'oemerian'l.ls-each m eE,l· 
---------------------------------------------
I HAlofyt-Stndier. p, 250. 
284 THE PLANT CO'-ERING OF OCRACOKE ISLAND_ 
tome bundle is provided ,yith a well-marked mestOllle sheath nnd, 
outside that, a parenchyma sheath. 
'Vhe n we compare the ~pecies helonging to Ule two formal ion 
classes, sand-strancl and salt-marsh, we filld that a majol'itr of both 
hlwe sevenll characte rs in common , a.ll of whiCh .tI'e llist-ine tly x{'t'o­
phytic and are usunUy interpret-eel as protecting the lt~nr agninst. 
excessive t.l'anspirat ion as well ns t.he effects of too inteuse li~ht. 
Thesn are : Thi.ckened len,~es, thickened cuticle, HlHl deyelopmt'll t of 
tlw chlorophy ll ti:-ls nc as compfi,e t. palisade on the mos t. exposed sm'· 
face or snrfnees. 
Morc nU1l1et'on~, howevc~ l' , HI'l' the diffel'('ntial cha racters. The 
lenveH of tI)(~ sllud-straml species are usually b ira.cial, with stolllata 
only on the dorsal ~urfac€t or, if Oll both sUl'ffi,(-'es, protected uy R hairy 
eovering or lying in deep furrows; and t he palisau.o is situated on 
the moro exposed upper 0 1' ventral siue of thc l<.'uf. The I"nlt-mfl l'sh 
species, on the oU1('1" lumu, ha\'c mostly isolateral lca.n~s , n :-I'ti .. ' al ur 
nearly vertical in position, with stomata And palisade on hoth sur­
faces, and (with olle (~xce ption) lacking the ,le nse hail'Y covering. 
Conformably , the most common grass of the salt marsh, Spur/ina. 
sf.1',cla, othcl'\dse ~o similar in leaf struc ture t,o the dune form of 
S. l)Qiens, hn8 no hairs lining its st.omatfll furrows. The cuticle h~ 
wrinkled 01' WUl'ty in lUallY more salt-mal'$lt t,han sa.nd-stranu spec,ieB. 
'Vater-storage panmchymn, which is notably developed in the sand­
strand vegetatioll only in the monocotyleuons, is present in fi majol'ity 
of tho salt.-lIl1u"h plants of t.he most. <live l'Se relationship. 
Corresponding to their growth in usually open formation, Rnd (:on~ 
sequently grun.te r (~xpmml'e tt) t he wind, the saud-st.ru,nd pla nts Hhow 
a JIl1.wh st.ronger development of stereome than do the t:lnlt-llIRl'sh 
species. On t,he other hand , the latter al'e hett.t'1' provided with hypo­
dermal collenchynm, or collenchymatic tiss ue, opposite the veins; but 
this lIlay be more importaIlt as a protect ion against loss of water 
than aM a mechanical strengthening tissue. 
It should be emphasized that not only the peculiarities common to 
plSlltM of the two format ion clnsS{"s, but likewise most of theh' l'PsIW'c­
tive diffp:rentiA.I, (']lA.racters, nre really of II. xerophytic nature, I In 
some eases , however , a different means h?ls been employe(l hy l'Il\ nd­
s t.rand sl~ies on the one hand awl by salt-nUll'sh ~pp~i ('s Oll t he 
othCl'1.u secure the same end-protoct.ion a.gainst t':X t:~ssi\·o trallspi­
rat ion antl Ute hRrmfll1 action of too int.emw ligllt. 
_ . _. - "_._'. .'. _. ' ... - . 
1 In his most r ecent paper on the subject . Warming (Hnlofyt·Studier. p. 235) 
writes : .. It is not pO!",~ible, froUl the investigations here described. to draw any 
clear distinction between charucters which are truly xerophytic and such R '4 are 
truly halophytic. if any really e xist, " Schimper (Ptlanzengeogr., p. 9'J ) also hoida 
that halophytes can not be d btinguished as a class frow. xerophytes, since the 
principal object of the peculia rities of structure observable in plants growing in 
saline ~iI, however moist. is the r B(l uc tioll of transpiration, just as it is in plante 
stll'l'otmded by a physicMlIy very dry soil and atm08phel'e. 
ANATOMY OF SAND-STRAND SPECIES. 285 
SPECIES OF THE SAND STRAND. 
PANICUM Al\IARG:\I EII.t 
J~eaf bifacial, strongly involute when dry, midrib not prominent on 
the dorsal surface and not much so on the ventral surface, shallow 
furrows (deepest each side of the midrib), with broad andronnded 
intervening ridges on the ventral surface, correspollding to very 
slight depressions on the dorsal surface. 
Epidermis: Ventral, similar to the dorsal, but with thinner outer 
cell walls; stomata at each side of t.he group of 3 thick-walled bulli ­
form cells at the bottom of each furrow; hairs nonc. Dorsal with very 
thick, porous outer cell walls, 1 or sometimes 2 short cells alternating 
with long ones, except in the rows containing stomata; stomata lying 
in the shallow furrows, with walls of the guard cells much thickened; 
bail'S none. 
Subepidennal stereome in large groups above and below the midrib, 
that above separated from the hatlromc by several layers of thiekish­
walled, colorless parenchyma; smaller groups above and below the 
other nerves; strongly developed in the margins. 
Chlorophyll tissue (palisade) arranged radially ill a single layer 
about each mestome hundle, almost completely encircling the smaller 
nerves, interrupted above and below the larger ones, each 2 neighbor~ 
ing rows of palisade separated by a single layer of colorless paI'en~ 
chyma~ chlorophylllikc"'ise occlIl'ring in the cells of the parenchyma 
sheath which adjoin the palisade. 
J.llefitome bundles surrounded each by a lllestome sheath which, in 
the larger veins, has all, or nearly all, of its cells with walls (especially 
the inner) strongly thickened; mestomc sheath in turn surrounded 
by a lal'ge-celled parenchyma sheath; mestome parenchyma in a single 
layel' of thick~walled cells separating the hadrome from the leptome . 
• 
. MUHLENBERGIA FILl PES )L A. Curtis. 2 
Leaf(tig. aH)conduplicftte without power to unfold, appearing as if 
terete, slightly asymmetrical, mHrgills almost meeting above the mid~ 
nerve, and hence only the dorsal sllrface exposed. From the slight 
opening between t.he margins to 1 he midrih extends a lllllTO\Y fissure, 
with lateral furrows hetwt'en t.he lal'gPl' nerves reaching Blore than 
halfway to the donml surface of the leaf. The ridges above the 
mestome hundles between these flll'!'oWS aro hr'oad and 1'00IJlIled at 
apex, except that of the midnerve, which is na.rrowed olltward (hence 
conical in cross secth.'ll). On the dorsal (outer) surface are narrow, 
IThe typical form of this species was not ohserved upon Ocracoke Island. but 
the leaf of val'. 'min1t<; Vasey & Serilmal', which was collected there, correspllD(is 
in every d",tail to that of the type. 
~Compare Volkens's figure awl de8criptioll of Aristida ciliata (Fl. ~~gypt.,pp. 
49,150, t. 16.ff. 4- to 7). 
2!S6 THE PLANT COVERING OF OCRACOKE I~LAND. 
sUt-like furl'ows between cacll 2 nen-es (hence ~ to e\'el'y \·cntrn.l 
furrow), opening iuto wider airspaces with stomata at ~ach side of 
the hottom. Stoma'" nlso oe· 
cur nenl' t.he bottom of the yen­
tJ'al furrows, Imt are there less 
TMlmerous. 
Epidermis: Ventml (fig. 3~) 
with cell walls thinner than on 
the dorsal surface, mKlly of the 
cells extended into st.raight or 
curved, spreading, unicellular 
hairs which line the main en,~­
ity and Inter"l fUlTOWB with 
a dense cross work, and nre 
larger, thinner- walled, HIH.I 
moro slonder than those which 
occur 011 Uw dorsal ~mrface; 
Imlliform cells none. Dorsal 
(fig. 35) with smaller cells, the 
outer wall and ('nticle so FlO , rn. __ Vu/ilntocryitt jili/wlI-trau6VCrSI' section or 
leaf. &a1e 75. 
gl'<.'ntly t,hickened as nearly to 
equal tho cell lumen, lhe areas lying above the subepidermal strnlHh; 
of stereonw having' singl .... I'OWS of short cells whi('h alt.ernate with 
seyeral rows of long' ones; IIUlllY of t.i1C el,ith'rmal cells extended into 
short, stout, )loinh'd, t hick-walletl , l1nic(\llula 1', appl'e'ssed, lll'ickle ­
• 
'FIG. :14 . . \lIIJiI"IIIH·r"iu Jilil"'~­
"(lutral epidermis ot It'M. 
Ttan~vi"r~ SI.-"(·tion. s h owing 
tbe hairs. Renl'llth the CI)I· 
derml~ nro In)'ersor ('"I<lrle!'l.~ 
l'lar~llch)"mK. SeRle 4t_ \' 
Hke IIn,i I'S, which Ihle the ful'J'ows. 
Subepidermal .')/I'I'emne: None on t.he 
"antral side of the leaf and in the mal'gin; 
)SI 
FIG. :r,. - .If ul. I, ' u/H:'ry iu fililJl'.~ -·dor1S141 }lInt 
of ) .. al J,la1le. Trnn'<\"t'rJ;C t",dioulIlI(>w· 
inK tlh~ epi(It'rmi~ (RI). ), Nt"I'\'OlUO (Rt . I 
• 
Iml1 1';111.1('1' lhid, ·wnllecl,'ulorlCil;Ji PAren· 
chyn.n, I P;\. I, whi!":h hurdt~r!t 011 tht· 
IllL"StOl)H~ hUlllll.,. ~·alt. 41n 
on tht': dorsal side i II the forlll of ftattene<l support i IIg strIL1Hls I 
be neath the mest.onw hundles, passing gradua.lly into the often 
_ .... _--
,~ . -- ..... 
I" Abgeplu.ttete Triiger, ,. Schwendener, Meehan. Prine., 11. 40. 
ANATOMY , OF MUHLENBERGIA. 287 
t.hick-walled, colorless parenchyma which separat,," it fnlln the me8-
tmne sheath. 
Chlorenchyma (fig. 36) consisting of small, hranched ce1l8 with small 
intercellular spaces in n single la-yel' radially arraug'M about, ('a.ch 
mestome bundle, lying only at the side~ 
of the larger bundl ... , but extending 
in horseshOe form around tho ventral 
(hadrome) portion of the smaller ones. 
Parenchyma sheath of th.. mestome 
hundles, whero adjoining chloren­
ehyma, also containing chloropbyll. 
Colorless parenchyma (fig. 3ti) occu­
pying the lIIl'ge,' yentml ridges (oyer 
tho larger meslmne bundles), and in 2 
or:J rowS of cells between each 2 nerves, 
extending from t.he ventral In the dor­
sal furrows. Also in 1 01' 2 rows sepa.­
rating the ehlorenchyma from the P"­
renchyma sheath of tbe smaller hun­
die,. 
Jlfes/omebundles (fig.36) with a large­
celled parenchyma sheath; mestome 
shC'ath none, but mestome pal'C1whyma 
FIG.30.-_lfuhlcnbel·gia Jilipetl-portion or 
Jnestome bundle. Transverse section 
or blade, sbowing a part ot the leptome 
(Lept.). till' Ilarenchyma sheath (P). 
the ehlorencbyma (Mes.), and the col· 
orlU>l8 pllrencbywa. (Pa.) between tbe 
mostome bundles. Scale 600. 
with cell walls (especially thc innel') much thickened, surrounding the 
lal'gf'l" nel'ves, simulat,iug a mC~J t,()me sheat,h; ma.ny of the compRllioll 
celiM in the leptome very thick·walled. 1 
I The two specioo of Mnhlenberg-is most nearly allied to Jr. fililJf. ~/'J are .. :1f. CalJi/­
lari.'$ (Michx.) Knuth and JI. triclw}wues (Ell.) Chapm. ChapmAn regards ]JI. 
jiUj)f!R 88 a vs.rietyof ll[. capillaris, but the striking histological differences, together 
with good morphological (:haracters, show that ill ~l[. Ji-lipes we have a perfectly 
vaUlt species. 
A comparison of the leaf anatomy of the three furUlsgives some v~ry tnteresting 
results: 
(11) .11. ('nl'ill(lri.~ is a plant of ury sandy or rocky (eugeogenous) soils, but the leaf 
shows only feebly the "t.rlmg xerophyti(~ !'Itructure of Jr. filipe.~. Material from Great 
Fal1M. Md., was shHlietl. LeA.ft.hinnc,' than in M. JiliJ}l's, conunplicate when dry. but 
fiat when well supplied with water. Ventral face not furrowed, fl1rrows on the 
dorsal fRee extending nearly halfway through the leaf, with I)tomata. at bottom. 
EJ'if/(,,.mi.~ moch a s in Jr. ,1ilipes, bot. \vitb bullifofm cells between each;! ner\'es ; 
bairs much fewer thall in.lilipl'R, all lihort. thick-wH.llcd. pointed, antI prkkle-Iike. 
occurring on the ventral face only above the nerves, on the dorsal fa.ce lining the 
stomata-bearing furrows and there thicker-walled , with hardly perc~ptible lumen. 
Subepidermal stereo-me in flattened supporting strands above Hlld below the 
mestome bundles, froUl which they are separated hy thickish-walled, colorless 
parenchyma; and .aIMO in the Jent margins. 
Cltlorenchym.a as in.flljpc.~ . hut entirely e.urrounding the swa.ller bundles. inter­
rupted by colorless parenehyma above and below the larger ones. Also mueh 
chloropbyll in the celh\Of the paren(:hyma. sheath which adjoin the chlorencbyma. 
Me.'!tome bundle.'! with uo true 11le~tome sheath. lJUt mostly surrounded by a Sill-

ANATOMY OF SPAR'l'INA. 289 
flll'l'OWS, whieh arc :J-dpft, at hottolll by Ute low I'i<lges of t,he 8IJlall('~ 
II<'ITCS . 
_")pideI"1Il1~"": Ve nt ral wi t h cells muuh smallt}!" and thinnel'-wall(!d 
Umn 011 tho dorsal snl"fa(~e; sl,ulllata. 0 11 •. 'a.ell side of the bottom (If 
til(' f tll'l'ow:-i, somewhat pl 'omi1lent j mallY of the cl'idennd.l cells 
extended into short. I'ath e r thin-,vallcd, et'cct, unicellular papillae 
wit,ll hroad, l'otllHle.l 01 ' t I"lIucat.e sli m III it-!'i, H.IHl, especially at -the 
";Ulllllli t of the ridgmi, illt,., longer, sharp-pointed , thick-walleu, ereot, 
l)l'h~kle-like hail':; ; typieal htdlifol'lll eells 1l00HJ, hut at the bottom of 
eaeh ful'I"ow it gl'oup of llsnally 3 lal'g( ~ epidermis eells, which arc 
IH'uhably fUJu,tivnnlly hCII I U)lf.gUliS. I)nrsal wi th thick , porous walts, 
whic h, in the 1'0W::; cOHtainiug :-;toma.ta, are unevellly thickened so as 
to ilppt!lU' wavy, 1. or mOI't} oftl'll:! :-;luH"L (~e1l8 alternating with the 
longol' OIWS; cuticle thick; stomata in very shallow furrows; hairs 
Iwd papitlau ilOI lO. 
SlllJepide-r11tal stereo1JU! Ho t. a~ stl'ollgly developed as in most of the 
strand gl'asses, ill small g-rollps on t.he dorsal side of each nerve; in 
ftaU,eu ed supportillg" stntlllls at tho stlllllllit of each vcnt ral rib alJd 
extending some di1"tallct.! down its s ides; and in comparatively small 
st.rands in the leaf ma.l·giIiS. 
Chlorophyll ehietly ill tho parellehynu\. sheath of the lllestome bun· 
(llcs, wi t h a "bridge" of small-('ellctl ('hlol'enchyma connecting cach 
two ne ighbol'illg' sheaths ; palisade none. 
ColO/·less pa1'e1why"w filling tllH vont.ra.l ribs above Ute mestome 
bundles where i t interrupts the parell<:hyllla sheath, a ft;,w cells also 
int.el'l'upting the pal'enehYlIIlL sheath on the dorsal side. 
l1feslome lnt1ldle.'1 Slll'l'oUluJo(l In' a. mestomc ~hcath whose walls 
• 
(especially the intwr) art· much th i('ke nec1 only on the lcpto me side 
of the larger nerves ; panmehyma sheath (enveloping the mestome 
Rheat h) containing chloroph yll , eOllti nllOl1S ahout t he smallel' nerve~, 
illte l'l'upted hy colorless p", .. e lldlym", auo\'(~ awl be low t he larger ones; 
mestome parmwhYllla ( t.hi (~k -wa.lled ) i ll il, singlo laye r between the lcp­
tome HIl(l tIl(' ha(holllC of l"hn lal'gm' hllndles. 
S J'AH"'J'I:'\ ,\ S.T HlC'I'A (Ait..) Rot h . I 
Lpaf ('OIl1lllpli"Il-le wlwlt Ill'.\", no t flll'l'owed 011 lhe dOl'~al :-illl'fu.ce, 
dt'pply fUlTowc(l (Ill lhl' Hmlra! sid e, IIH~ flllTUW S aeul,· , the ill to r­
""lling' r idges hl'oad allll1.,.tIlH'HII~ at Sll III III it.. 
A'pitTt) rUl/~: V t' ntr .. 1 \\"illl (·I·lls JI. lITlnv,' ,· ami Ilot S« I hig-h :IS 011 
the dOI':-;al sul'fa(;e, 1"110 wall:-i as ill S. jUdl' II.'i, eXt~e[Jt .. hat tllP olll,(H' 
wall of each ecll i~ eovered with :-;ilie ilictl papillae; stolllata on each 
side of t.he hottom of t ho 1'111'1'0"":-; ; hail's nOlw ; typical hull!fol'lll eell!i 
Ilone, but 1 to a el'iuerilla l ct.dl :-; a t buttolll uf each \"coLt'ul fu .... ow 
somewhat larger tha.n t.Iw uth('I':-i awl pl'ohahly functioning- as bulli-
1 Although this species belou "'{8 to the salt marsh, it is described here for the 
sake of cOllvelli ent ('omparisoll wilh th· oth r (Tram"neae. ComparE' DllVlll ·J ouve, 
His totaxie, 1'1, 1S. Ji!J . .. ,. The O'Tl(·ok ... plant. i ~ II carly of the typit~:-t l fm m. 
'2Ufj5 ;j 
2!lO THE PLANT COVERING OF OCRACOKE I~LAND. 
form cel1s. Dorsal as ill S. lJuteus, the short cells II:-<u<llly single, 
hero and there rounded , with strongly thickoned walls, almost for'm­
ing papillre; stomata none; hairs non e. 
Hypodermal colorle."Is parenehyma in a single 1ayol' hew'at h the 
dorsal e pidermis, 1 illt(~rl'uptcd by Ruoo))idennui ste:reHIlW. 
Sfer eume not. st.ron:.:)y developed, a small Stl bepidermal g-J"OIlP on 
the dorsal side of each lIlest.omc hnndlt~; flattened support-hi.!.!' :-;tI'allds 
(I 01' 2 laY0r:i) at the summit of ea.ch ventral ridge, Hut decurrent, 
a.lon:.: it..-.; sides; also in the leaf mal'gins. 
Chlorenehyma cOllsistillg' of small palisade eeBs il1 a singlo layer, 
radially Rl'l'angcd on 4-lnch side of each mestomo hundle allu {!xtcIlU­
ing immediHotely beneath t.he epiuermis to tho st.Cl'oome at the summit 
of each ventral ridge; each 2 neighhoring layers of palisade, hetween 
each t,wo nerves, t\ithel' adjoining 01' separa.ted. 1>ya fe w, lal'g(" coloI'­
less parenchyma cell"; chlorophyll also in most uf tho cells of t.ho 
parenchyma sheath. 
Mesiome bundles with lUestomc sheath and mestoIDc parenchyma 
much as in S. patens. })al'enchyma. shcat,h (aruund the mestowe 
sheath) of largo cells, t,hosc adjoining the p"lisade lltyer containing 
chlorophyll, Ute sheath occasionally interrupted 011 tho dorsal sidc of 
llC 
lo~Jo. :t1.- Chinn' .• pd l'(le(t-l~a.f lllA.rlC'. TrBUl'lverflO !lection, show· 
ing tho tnillrib ill tho keel, co\'el"Q{l by layers or colorless ti~· 
Bue and 0. iCrouP ur hulJirorUi ('ol1s (00) on the \"entral Mur · 
(ace: 1H'. n I'Ilnall)CroulH,t hullitorm oell~ between twonu ... -s.,nm~~ 
bumUI't8. Tho mestome bunllles II.rc lndicau·(\ hy thulr l 'IlN' II · 
chyma. 8beaths and l,y the Mt l! rl~Omtl, which torm,.. I"wllll Rll1>· 
epidermal groups. The thkk wllllod mostome sheath lsdl'll.wn 
only in tlil' two 1Iu' Bo hl!lIdll.J~ . Sf~!\lo t4. 
- -
- - - - ._- - ----
the bundle by " few 
cells of tho au bepider­
JUal stor(lOllle, TAl.l"g'O 
parenchyma. C('lls, in 2 
01' i3 layel'~, occupying 
the thickness of the 
vcntl'all'idgcs a.lId ap­
pearing t.() be an exten­
sion of tho paren­
chyma shen-th; when 
in 3 layers, tho middle 
Olle (·olol'less. 2 
( ;HV 'I-tISPKTKAEA Sw.3 
Leaf (fig'. 37) beeom­
i IIg ('OIltl uplieato wll(m 
'The gpecimen figuretl by Duval.Jou\'e.loc.cit .. hl\s :! or ;llayerH. 
~SP(U·tiu(l Ntl'irtrt 11WI'itilJlfl (WaIt.) SerHm .• the ('oillmOIl funD cl!'!ewhere alollg 
our Atlantic CO,\st, is pradically ide ntical in leaf HlIa.tumywith S . Nt!' i", t" from 
Ocracoke. except in the foHowing parth-ulnrs: Thp. epidermis cell wa118 on th(> 
dorsal snrface are thinner an~l less porons antI "huw less of the wayy thicken· 
ing; the short cell" are m ore often in pain! , !-l.ud. when sinj.d~" lire more often 
papilliform; ster(.'Ome is somewhat m ore .strongly developed. IIH would be expected 
from the larger si:-.e of thf! 1118.Dt nnd the gre.~ter length of tbe leav~, The mat& 
rial examined was from Lynnhaven Bay, Virginia. 
;'Fignretl by nllvnl-.Jollve. Histotaxie, p, ~;);\ 11[, 1S, .r . .1, For an oxample of 
similar h'ar ."itrll c turH com));Ire the ~lUe nnthor's pillll.'r . .. Etuue hiHtotaxi~ll1o d~ 
CYIi6TU8 de l<yance,"' Melli . de l 'Acad. de Moutpelher, tome -; _ pl . .!.!.!. (J, 18;4. 
--
ANATOMY m' CHLORIS PETHA.;A_ 291 
dry, st.rongly kt.'d,·d 011 t.lu). dot'sal fa.ce and ~1ightl.r illllU'cssed Yell­
traIly opposite tlw lIIit.1n·in. with a laI'gp lIIestoluC hund le at t.h ~ ape x 
of and ;~ ~mallel' on('!oi 011 e.wh side of tlu' keel. Hail's nOne. 
Epi(Ze,..mis: Vt~ ntt'al, tlirrc~l'cnUate(l as lmllifoJ'm C(.~ 11 s in a ,'a.the r 
wi(le band abo\"() the kePI ami 
in :! small gronp,~ of ahout, -I- .. J~ .. .. , . 
cells each, 1 h otWPl ' 1i t he Ii "st 
pair of nerves on each sitlp of 
t.hc keel; elscwhcl'C I.itl !'it'cll H­
Iar (3 or 4 layers) alld 0'-'-11 ' 
pying more thall OIw-half of 
the thickness of th(~ h'ar, t \:\ ­
cept above tlH l larger neryos, 
th i 11-walled (ex copt t ho outer FIG. 38.-Chlm·i~ l"oc.'~nH·(I '-- vlllltral p(,.rtion ~r lea.fblade. 
TI'A1I8\-er.m fII...'(:tlon, " llOwlng Olllde rml51 ( Eo))) and 
wall of the oute rmost layor) MlLeIJidermal s tcrt'o mo (St ) : at j( tho mestome 
n.nll large (exeept the sin 'yle i"h.'ath of a Illlnulo, lMJl"del'ing on layers of colorle88 
!") IIlLl't!lIcbymn. Scnlo ::W , 
outermost la.ye r wlwl'e it lies 
• 
above the subepidermal grollps of stel'eome); st.omata none. Dorsa.L 
epidermis one-)ayered , 'with cells all small , the ol1tel' wall and cuticle 
much t hickened, I'adial waHl" thin, uTIIlulate, one I'OW of short cells 
with strongly si1icificd walls al t('l'nat i ng- with seve l'al row~ of long ones, 
many of t.lw cells df'v('lopNl int-4) l'OIllHlcd, not silicified, pn.pilJac; 
L _ _ _ _ " .. ""''. _""" 
Y. . .. . .. -. 
.. _-- -- .. .. \-.. 
. -.. p 
____ V 
stomata in Lhe strips of epi­
dermi s whi ch lie between 
t.hc n Ol'ves, loyel wi th the 
epidermal surface. 
Subepidermal 8t"rfmme 
(fig. :JR ) ill flattened sup· 
port,s above and helow the 
me!'Jtome bundles, that on 
the ventral side ill 1 01" 2 
F 11; , :111,· c/, I "rill /><' f "111'" lal'l:t' l llll's t mllO 1,u 11(1 Ie j '}', 'Ill It ,; d' 
IJlad.,. St. J.l ll!n'mml of low"r ( ;Ic e or I,b .lo-. I ... r,krillg' 1111 
t he In('St. '.tnc l<iU'lltli ()I ) , whk h l1 11 "i r ,'!. 'i" I",th tile k ll ' 
t,)me and lUlrlrome tl.R li. d Ol!V'd slWltTb of thkk·wallcol, 
layers above the larger 
nerves, reduced to small 
groups (8ometimes only 2 
C(·lIx) auo\' (~ Ule sma.ller 
olle~ i 011 the dor':-:;a 1 side 
SlIVPOlts st rongel', some­
tillu's iJ-Ia.yc l,t...'iI ; a.1~o in 
the lea.f margins, 
porous oolb, Borch.' r ing' on tlw JlIl ' s I UIll" " Iw(lth io,! a 
,reen pat'(lnchyma flbeatb (p " VV, \' . !~ ... !IR: L. h"~l1l1' l 
with an annular ves&ll. S<~"1 \1 rJf,o. 
('h/01'f'ndlymCl-, pal h"ado, 
'~L'l'alJgl,tl radially ill It sin­
g-Ie row of cells 011 ea.ch 
side of each mest.omn hHlHlI(\, with a ''In'iuge n of !'4lllitH-cellcd ('hlo­
renchynm, containin~ usually a fow eells of colorless parenchyma, 
conllect.iu~ each 2 lI e ig-hhol'ill~ rows; dtlorophyll likewise in tho 
parenchyma !'4beath whc l'o it. adjoins the p'ulit:laile. 
292 'l'H~: PLANT COV~:RING OF OCRACOP: ISLAND. 
MesUime Intndle., each inclose<l by" mestome she"th (figs. ax, 3\1,40) 
which lilt.' small cells wit.h equally t.hick.med walls; parenchyma 
sheath with large, t.hin·walled cells containing chlol'Ophyll where they 
H.tljoitl ,UlC palisadHj mestmne parenchyma in H. singh~ layer ~I.'pa­
I'ating tlw hadrome from Uw lcptome of the lal'g-er hllndles; eU III ­
pan iOIl cells of the sieve ttl ues with IIllwh thiektHw<1 wflll~ . 
. '
• 
. " '1 . 
" 
• 
• 
"p 
n. b. ", 
1"10 . .fJl - Ch/llr i tt petrat'a-thr~ Arnall mC8tome hun.n~ from the blade. (Lettc~ lUI iD fig. a&l.) 
[n a tho mOlltome sht>ath h< thick· wallen only on tho leptome Aide; In band c thl\ thkkening o~ 
tbe Dl6$ltome sheath iA ,"01'41 ilistinct and begins to show also on the b .. drama Ride. Tho sheath 
Is e1Of1etl iu all of thBllO 8lDAII bundl08 and ill a trne IDestome sboath. Scale 500. 
UNIOLA PANICULATA r..' 
T.eaf raUH'I' thiek and hurt}, more or less involute when ury, deeply 
fUl'I"owed Oil the ventral surface, the interve ning ridges broad And 
trnIlcat,(l 01' but slightly rounrle<l at summit; dorsal surface with very 
slight C01'l'eSllondiug cleprc:'!is ions. 
Epiderm';',: Ven!.ml wit.h cells smaller and !.hilmer-wall",] than on 
the dorsal ~Hrfaco, the outer walls more archetl, !Han.r of the cells, espe­
ciallyon the sides of tho furrowM, extended into short, stout., point.ed, 
unicellulal', ant.rorRll, prickle-like hai!'!' with cuticle rough and exces­
sively thiekene.] (lumen almost obliterated except toward the base); 
stomata lI~ar t.he hottom of the vent,ral furrows; bulliform cells in very 
small grOl1[lH a.t, t.he bottom of t,he furrows. Dorsal with cOllRpicuottsly 
pitted walls and very thick,;2 strollgly wrinkled cuticle, 1 Ol' sometimes 
2 or 3 !o\hol't. colis ait.ernating ill the Ma.tllO rows with long ones; ha.irs 
none; stomata lo.-;.'i numerous than on ventral surface. 
Stereollle strongly developet! (rnor'o 80 than in any other of those 
strand gl'aS~WH); s1 rong, flattened suhepidermnl :-Iupport.s at tho su m­
mits of Uw ventral ridges, sopal'ated fl'om the mestome huncHes by 
t . hill·wallt~(l eoiol'lps."I parenchyma whieh abo contains small, isolaterl 
gr'oup~ of stCI'OOIllO; nnl'row, mosU,)' 2-1a.yt~ red sllIK~pitlel'll1a.l g"oups 
on t)w d01'sal side opposite the venim.l furrHw!oI ; !oitrong snhcpicle l'lnal 
xnppol't.s on the dorsal side of mlch mest,ollW hundlo; finally, strong 
mA1'ginal g'1'OUpS. 
Chlorew:h!Jlfut: Palisade small-cellec1, n\.dially disposed on eiWh ",iut» 
of esu:h nwst.ome hUlHl1e ill ~inglc layoJ's, which arc perpendicula.r to 
J Compare Holm, Bot. Gaz. vol. 16. pl. 2J, If. 8 to J!:!, 1891. 
t But much less 80 than in Holm's materia.l from Fort Monroe, Va, 
• 
ANATOMY OF YUCCA. 293 
the leaf surface and extend nearly to Uw summit of the ycnt.nt.ll'iuges; 
inside the laye,' of palisa,le, and parallel to it, is a single layer of largo, 
thin-walled parenchyma cells cont"ining chlorophyll, which represents 
an imperfect parenchyma sheath to the mestome bundles. 
CohYl'less l>arenc/tym,(t in stwcral la.yers which lie below t.he ventral 
furrows and snparn,te each two neighlJoring' Jayel1-i of palisaue. 
Mestom e lnuulle,'; without a. tl'lW lILestomo sheath, but with the lep­
,tome SUJToutl(h~d by an unbroken rin~ of mes­
tome parcnchyma having small cells with thick 
porous walls. 
YUCCA ALOIFOLIA J~. 
J~eaf isolnter'al, thick, e~pecially t.oward the 
base, ending in a rigid apical spine. 
F:pitlermi.'i (fi~"8. 41 , 4~) ('(~Hs containing chlo­
rophyll, m~tly somewhat dong-atcd pa.ra.llel t.o 
t,he leaf axis, their wall:-i, (~~pedally t·he arched 
outer onos, greatly thi ck pned a.nd, together with 
the massive cuticle, excct,'()ing the cell lumen, the 
radial walls not undulate; cut icle sharply ,liffel'­
entiated, beautifully stratified, divided by per­
Fro. ·u- rULe« u/'Ji/ulif' ­
lear surfl1co. Eplderml~, 
sbowinl{ openingI:' 1,,0.11· 
fUll tothestomata. Scule 
""'. 
pendicular lamell", corresponding to the radial cell walls; stomata 
deeply sunken, lying beneath the cuticlo Itt the bottom of urn-shaped 
passages whoso outer orifice is quadrangular ,vith raised, cushion-like 
bordm .. , tho ridges of exit at bottom of the pore very acute; papiJIw 
none (perhaps present in younger leaves) . 
Interim' of the leaf occupied by homogeneous, thin-walled p""en­
chyma, which, toward tiw apex of the leaf, contains chlorophyll in 
its entire thickness. 
Mesfome bundles lying ill several rows in the mesophyll, each sur­
rounded by .. parenchyma "heath. 
Stereome in massive groups 011 both the lep­
tome and the had rome side of the bundles, espe­
cinlly ~f:.l'ong on the haurome side. Small bnn­
dIes of stercome, each with a parenchyma sheath, 
a .. " scattered among the mestoOlo bundles. 
YUCCA GLORIOSA JJ. 
Leaf much like the prceeding. 
FlO. 42.- Yu('oo nloifolin­
a stoma. UrOHH·tI{lI.!tion. 
Scale 320. Epidermis with larger (highcr) cells; dorsal 
surface bearing thick, rounded, l-cellcd JI"pillal. 
Apical spine with ~xe(,"Cdillgly thick outer CI)iderrnis walls and 
cuticle, these much higher than the cell lumen , radi .. l and inner walls 
also much thickened; next a hyp<~lcrDlal layer of thi"k-walled col­
lenchyma; then 1 or 2 lI,yers of thick-walled collenchymatic tiHsue; 
and, finally, R. dense mass of titereome, inclosing a. limall centrH.I 
mestome bundle. 
294 THE PLANT COVERING OF OCRACOKE ISLAND. 
MY't!( 'A CAROLINENRIH Mill, I 
Leaf bifacial, thickish, both surfaces sprinkled with I'e~iniferous 
glands, appearing to Uw unaided eye as granules of resin. 
Epiderm'is: Ventral, cells small, raclinl walls not undulate; cuticle 
thick, smooth; stomata nonc; long, pointed, unicellular hairs with 
thick-walled, smooth cuticle scattered along th(~ veins; short-stalked, 
superficially fiat, scale·like, pluri,·<lllular glands occupying deep 
depressions but usually rising ahove the level of the epidermis, these 
filled with a mass of bright-yellow rosin which bl'eaks down the cell 
walls and finally itself disorganizes, the stalk of each gland radially 
surrounded by uumel'ons small foot cells. Dorsa.l simila.r, but cuticle 
less thickened, glands less numerous, and stomata present, lying in 
all directions, each SllrrOUll(led hy 5 to 7 ordinary epidermis cells, the 
guard cells slightly prominent. 
Chlorenchyma sharply differentiated into one very compact layer 
of palisado with high, narrow cells, and several layers of open pneu­
matic tissue with rather Im'ge intercellular spaces. 
. . 
Colorless t.hin-walled l)(tTf!nehyma in narrow plates interrupting the 
chlorencliYlIla a.bove amI below the sma.ller veini. 
Hypoderlllal coUenehymatic tissue, thick-walled, in 2 or 3 layers 
above alld uelow the mitlvein. 
Mestome bundles of mid vein reinforced by stel'come which adjoins 
both the h"drome and the leptollle, that below the leptome separated 
from tho hypodermal cullenchymntic tissue by It little thin-walled 
parenchyma. 
MYRICA CERIFERAL, 
Leaf usually somewhat thinner than in ~f. carolinensis. 
Epirlennis similar, but with fewer hairs a.long Uw veins. 
Puli.'mde somewhat thicker, ill g layers of lower cells. 
QUERCUS VIRGiKIANA L.' 
Leaf pm'Sistent, thick, bifacial, upper surface shining, marginR 
sometimes revolute, veius, especially the midvein, prominent beneath. 
Epidermis: ,,.-eIltral with Ilonundulate cell walls, the onter, espe­
cially, strongly thickened; outielo thick, smooth; stomata none; hairs 
none. Dorsal, cell walls as on the ventral surface; stomata with guard 
cells slightly promint'ut, lying' in all directions, each bordered by sev­
eral small epidermis cells; hairs (fig. 43) forming a dense covering, 
stellate, consisting of 8 to 18 acute, thick-walled unieellula,r arms 
upon very narrow foot cells, cohering toward their bases /-iO as to form 
a. saucer-shaped scale. 
-. -
. -------------------
I Material examined from near Norfolk, Va. 
iQ. vtrewl.AU. Material examined was from lIenr Norfolk, Va. Compare 
Quercus ileJJ as described amI figured by Lalanne, Recherches, p. 3, pl. 7, if. 9, 12. 
, 
-ANATOMY 0.- ZANTHOXYLU)! CI,AVA-HERCULIS. i!l5 
H!JP(Jrlt~ rlll lI1os1.1y :.!-layt!l'l~d, ('ollenchymatk', eontinllOliS un 1Io1,h 
surfaces (l'al't~ly inteJ'l'lIpt.cd hy pa,lisaue), replacing the chlol'f.m­
chym<-L a.lld forming thick masses above and especially helow the 
midvein. 
Sle'l'emne thin-walled, in narrow plate:-; intel'ruptillg the chlol'c ll­
chyma. and extending through the lea.! opposite most of Ute smalle r 
\'(·ins; in strong masses ahove and below the midvoin. 
Ghlor6nchyma: Palisa<1tl eompad, mostly in 2 layers, passing- ~1'<ul­
nally into pneu1ltctt-ic Mssue of which only the low­
e.'Jt layer is comparatively open and shol't-celled. 1 
ZANTHOXYLUlI CLAVA-HERCULI~ 1 .. 2 
teaf bifacial, thickish, dark greell anel shining 
above. 
Epiderm'is: Ventral, cells largo, walls not undu­
late, the outer strongly thickened, the others thin; 
cuticle sharply defined, delicately wrinkled; sto­
mata none; hairs none. Dorsal, cells smaller, the 
outer walls and cuticle thinner; stomata wi th guard 
cells slightly prominent, lying in all directions, 
sUlTounde<} by 4 to G epidermis cells; hairs nonc. 
HypUlkrULal (.'ollenchyma with sLI'ongly thick­
FlO. 43.-Q!lt'Tcu.9 t)iroini,.. 
Qlw-stellnto hair trolU 
dorsal leat Sllrface. 
Viewed trom above. 
Scale 270. 
ened walls in 4 or 5 narrow layers above the midveiuj col1cnchymatic 
tissue in 4- or 5 wide la.yers beneath the mitlvein. 
Chlure'l1chyma: Palisade a single compact la.yer of short cells; 
pnellmat,ic tissue in 2 01' 3 1ayers, rather open. 
Oil resf!rvoin .. schizolysigenous,3 sca.t.tc red through the mcsophyll 
neal' the ventral surface, anrt large!" ones at the base of each illdolltaa 
tiOll of the leaf margin, surrounded hy ~ or 3 layers of thickish-walled 
parcllchYJllt\ with cells strongly comprCHsed parallel to the surfaco of 
the cavity. 
MeslO"ine bundles surrounded l)y n thill, interrupted sheath of stere­
ome, which is continuous and (in CI'USS section) crescent-shapod out­
side t.he leptome. 
-
--~ . ~. . - ~ ~- - ... .- . . _ - --
I QIU'rcw~ lam'i/ol;,t Michx. is a deciduous-Iea.ved species, COUlmon along the 
coast alit] perhaps occurring Upoll Ocracoke Island. Leaves froUl Cape Henry, 
Va. , !:lhow tho following differences from (). "l'il'g i llialla: 
.Epidcrmi.-;: Cutkle thicke1'; dorsal surfac'"! less densely covered with similar 
stellata hairs, their arms longer, more slender and much thinner-walled. 
Uolknchymatic hypoder1lt nODe except abo\'o the midvein. True colle1:chvm.a 
(hypodermal ) strongly developed beneath the mh.1vein. 
S h"'eome entirely surrounding the Illillvein , where it is lIluch thicker-walled 
than in virginiana. 
Chlorenchym.a: Only the uppermo~t layer typkal palisade ; pneumatic tissue 
more compact and with more elongated ('ells than in viryiniana. 
~Material from Virginia and Mississippi. 
~ Compare Solereder, Syst. Anat., p. 201. 
2lHi THE PI,ANT COVERING OF OCRACOKE ISLAND. 
CROTON MARITIMUS Walt. 
TJcaf flat., hifacial, hot,h slIrfaees densely co\'ered wit.h a gray, sc;tle· 
like pubeseence. 
l!..'p irlerm is: Ventrnl, eell!o:l sma.ll, walls not, undulate, Ulill; stomata 
\'PI'Y III1I1Wl'OllS, g'lHtNl (~t~lls Invel with Uw 4\pidt~l'lIIis. mwh Rt.Ollla ~IIJ'· 
b. 
a. 
I'ottuclc(l hy 4 epiciel'mal eells, 
of which ~ RI'£': difTel'clitiat,(~l 
as c l"esclmf,-shapccl sHhsiclim'y 
('ells parallcl wit.h the gum'fl 
cellRj hail'R phu'jeellulal', st.cl­
Jato, eOllsisting of along cy Iin-
(lrical stalk rising above tho 
sllI'faeo and eomposed of lIlany 
small eells part.ly of suhepi­
del'ma.l OI'igi Il , ft'om f,he I\}lieal 
0011 of which I'adiat,c in 1\ 
nearly horizontal plane lHl­
merons l1nicclluhtl'1 sharp­
pointed arms with thick, 
smooth cnticle, cohering near 
thei r bases so as to forlll a slutl-
FlO. U. ·· Cml,m marjfjmuI-ho.ir from dorMl I('af low cup. Dorsal, simila.r; cu-
8Ul' (acl'. fI , View fr u m abo\'o; f,. CTOI38 sectlOD; Ep., I 
epidermis; P, palisade. Sealo~U. ticle tlickened and grnnulal' 
Ulu1cI'neath the large veins; 
stoma.ta about equaIJy numerous; hairs (fig. 44) with less numerons 
and thinner-wa.lled arms. 
Hypoderm, none, except beneath the large veins, where severa] 
layers of thin-walled collenchymatic tissue OC()tIl·. 
Stereom.e, none. 
ChlO1'enchY1na: Palisa.de in one lay~r, compRct, the ccn~ ololl~R.ted, 
interrupted only by thick-walled, bra.nching, ticlnrutic idiobJastsj 
pne umatic t.issue of roundish cells. 
I'"EX VOMITORIA Ait. 
I~eaf evergreen, thick, shining and dm'k green above, bifa.cial. 
Epidermis: Ventral, cells rather high (but small in their diulllct,er 
paralll~l to the leaf-surface), the outer wall and cuticle much thick­
enml but not neady so high as the cell lume n, nldia1 walls I'H,t,ll(,'.r 
thin, 1I11rlulat.e; cuticle smooth; stomata none; ere(·t, short , stout., 
pointed,oflen curved, pricKle-Uk .. ">' unice llular ha.ir:-l with n~l'y t,hick 
walls (lumen almoAt obliool'llted) and ~ lIloot,h ( ~ lItiele :Llnng t.hc mid­
vein. I Dorsal, cells t"mallcl', thickel'-wall ed (Ol1tt~1' wall and enticle 
exceeding the cell lnmen in height), tim J'fL(lial walls nearly:st,l'ai}!ht, 
porolls j cuticle wrinkled; stomata very nn lIle l·ous, guard <!lllls slight.ly 
depl'cssed,; hairs, Hone. 
I This !!}lecie>l hI. thererore , an exception 
no hairs on the upper or ventral smface. 
. .. _-_. _._-_. --_._.. ---
to the rille that e\'ergl'een lea,'es have 
(See L :I:UUIIC. p . 111, ) 
• 
• 
• 
I 
ANA~'OMY OF TEUCRIUM NASHII. 297 
Hypoderm,at collenchY1fwt-ic fis,'HW in n single narrow layer RboY(~ 
Uti} lIIiuvcin (as ill I. opaca) and several layers bencat,h t.1w l..liuvein. 
Ohlorenchyma: Palisade in two layers; pneumatic tissue rather 
"IM'" (more so than in I. aquifoli",,, and I. opaca). 
Jlesimne bundle of millvcin reinfol'eed by a narrow g'ronp of st.eroome 
hfllow the lept01nf), awl n. l.himw,"·walled ~ronp a.hovn thn hadl'ome. 1 
OEN01'HERA Hl' MIFUSA Nutt .. 
J,e,,( ,Iensely silky-puhesoont, imperfectly biEacial, mirlvein slightly 
impressed above, not prominent, beneat~h . 
. Npidermis similar un both snrfaces, cell walls Hut undulate, some­
what thickenerl, especially the outCl'; euticle smooth; stomata with 
glll .... 1 cell. levcl with the upper slIrface, slightly prominent beneath, 
the majority lying parallel to tho veins, but many irregular; hairs 
densely matted, slIbappressed, lung, sharp-pointed, unicellular, with 
thick, granular cuticle, each radially surrouude,l by 5 or G foot eell •. 
Hypodermal col/.en.chyma in 2 narrow layers abovo and 1 wide 
layer beneath the midve.in, separn.t.ed from the mestome above and 
helow by colorless (water-storage?) parenchyma. 
Sle'reome, none. 
Chlorenchyma not sharply differentiated; palisade cont,,,ining large 
cells inclosing raphides, which "'''' yet more abundant iu the other­
wise rather compact pneumatic tissue. 
'l'EUURIUl\l NASHII Kearney.1 
I.eaf nOMna-liy horizHllta.l , bifacial, dark green above, white-toroen­
tOllS beneath, margins (especially in young leaves) Romewhat revolute, 
veins impressed above, pl'orniu(lnt and roticulated beneath. 
Epidermis: Vent.ral, cell walls thill, t.he lateral 1I0t undulate or but 
very slightly SO; cutide smooth i stomnta, none; hail'S scattered, 
mostly 3 or 4 celled, thin-walled, smooth, I1lender, very shal'p-pointed, 
strongly bent so a~ to lil~ lleal'ly pal'allel to the 8lll'fncc, surrounded 
radially by 4 to 10 (must frequent.ly G) foot cells. DOI"",I, cell walls 
mor'c nntlulate; stomata in the sheltered interstices between the pro­
ject.ing n~insJ with gllard cells sli:;ht.Jy prominent, lying in all direc­
tiolls, usually bordered by 2 epiuel'mal cells and at right angles to 
t.heil' dividing waH, hut wi th many exceptions; long-pointed hairs 
fOl'ming; a douse (~OVcrillg; a.lAo vcry numerous, 8phel'ical, sessile, glan­
dulal' hairs with roughened cuticle. 
Hypodermal culle1lchY1lwtic tissue in 2 01' 3 n"'TOW layers above and 
-- - - - - ------
---- - --- -_. -
'Specimens cultivated at Washington, D. C., differ in having 3 layers of pali­
sade, and no stereome above the hathorne of the IDill ,-ein_ 
~ TCllcriu7n canadcmw, which is m'lver, to my knowledge, a Btrand plant, differs 
ohiefly in the lcss (lenAc hairy em'erin,:: of the 11m-sal lenf Rnrface and in t.he dis­
tinct gn.nular roughening of the cuticll' in the pOinted, as well 8S the glandnlar 
hairs. 
, 
, 
298 THE PLANT COVERING OF OCRACOKE ISI,ANlI, 
1 wide laye,' bemmt.l. l,he midvcin, the lalte., !Klpamted f,' .. m tho lep- ' 
tome by several layeI'M of colodeAs parenchyma, 
Stereome, none. 
Ohloren.chY1TKt: Pa.lisado a. Ainglo layer of short liens, very compact; 
pnenlHntic ti~8ue occnpying- the 
I'est of the leaf's thickness, also 
I'ather compact. 
PHYSALIS VISCOSA L. 
Lear flat, thin, imperfectly bifa­
cial, gray-canesoont 01' green (de­
pending upon tbe amount of 
pubescence).' 
Epidermis si milar on both races, 
cell waHs not thick, the radial un­
dulate; cuticle ahove and beneath 
the veins thick and warty; stomata 
much mOl'e numerous on the dorsal 
surface; hairs (fig, ' 45) about 
equally uumerous on both faces, 
Flo. 4A-PhllWliB lluoo8a-branched hair trom thin-walled with granular cuticle, 
leat. Scaleffi. consisting of a. unicellulal' stalk 
bearing 3 or 4 (usually 3) conical, acute, uuicellular 0., sonwtimes 
bicellular arms, these in turn sometimes once-branched. 
Hyp<Jlkrmal. coUe1Whyrnalic I'issue above and beneath Uw veins, 
Sf.ereome, none. 
Ohlare1Whyma: Palisade and pneumatic tissue not well differen­
tiated, both compact, 
._-- ---------------
I The indivi.duale observed npon Ocracoke blaDd bed greener, 1ees pubescent 
leav6s tbsnat Cape Henry, Va. 
, 
• 
, 
• 
• 
• 
, 
ANATOMICAL SUMMAKY m' SAND-STRAND SPECIES. 299 
Leaf anlJ,tumy of ,'>fwd-st rand specicll. 
l The Kigu :< indicates l Jl'e>:lt;l JlCt, of cha.racter : +. Its imperfect development.] 
• _., -- • 
-'--'--'--'--
. 
Epidermis . 
Leaf. - , , 
CDtlch;~ • • 0 
-
. 
-
-
.. • . -- .. - • f • • 
• • 
" 
• .. 0 • 0 • -u • f .. • , •• ... • -SpecIe.. .. ~ ~ ~~ ~ • • 
" • u " 
-" • 
, 
... 
.::: ~ • 
." - E~ - 1 '8 , 
" 
- 0 ," B.g 
-
, 
• -. 
" 
, • • ;-.a - .... • • .. .. 0 . - .- • .. ~ u 
" " 
'" • 
... 0 • 
• .! u • .- -
-'l 0 0 · ;: 11 -- - • -
- iI • 0_'" .. ~ ~ • .. ~ 
"' 
0 ... 
"' 
.. 
· 
-. • .-
Pauicum amarum ._ .• ... . --------_ .. . , X --_ .. _- · X X X • •• ••• --_ ... .. ---. X 
Mublenberg!a tHipelL . ______ __ •• . ___ . . X 
---- -- --
X X X • ••••• .. -.-. --.. -. · -.... 
Spartina patens _ .... . . ... _- ---_ .... -- . x -... · -.. X X X • ••• •• · ..... ---- -- --.... 
Spar tina stricta I .••.•. _. ,_ . ---- --_ .... X ---- -- -- X X X • •••• • X •• ••• • • •••• • 
Chlor is petraea ... . . . ... _-_ ...... . ---.. X ..- · -_ . ---... .. X X • ••••• · _ .. .. x X 
UDioJa. panjculalM . ...... . ,nn ______ . . X .. _--- _. X X X X .--_ .. · .. --. X 
Yuc<:a a loiroUa · . -... ... __ ..... -_._._ .. • ••••• x x .. _. -.. - X • • •• •• .. _.- . _._ .. - • ••• •• 
Yucca gloriosa • • . . . ••• •..• _ .•••..... . . . • • •••• x X . _ .. -... x • •••• • • • ••• • .-._ .. • • •••• 
Myrica carollnenai8 . •• . _. _ . _ •..•• •.• _. X _ .. _ ... - _._- .... . _. __ . .. X • •• • • • -_ ... - · ..... ._ .... 
Myrlcacerifera_ .•••• ........ --_ . • • •• • • X .... . .. - ... _ ... . . _ ... -_ . X ._ .... -.. _ .. ..... - • •• • • • 
Quorcus virginiana • .. _-- _ ...... -.--- . X -. -- .... x . . .- ... - X · • • ••• • • •••• · ..... • • • •• • 
Z,nth oxylum cla va·herculis . ... _ .... X · ....... x . ....... x X • •••• • • ••• • • , .... -
Croton maritim U8 . . ... . -.. . . . . . . .. . .. . X · ... · ... · ....... . ... .... . . . ... • •••• • ± · ..... -..... 
n .. vomitoria . · ... • • •• ... ............. X ....... - X . ....... X X • ••••• 
" 
• • •• •• 
Oanothera humituu ... -...... ..... ... x ----.... .... • • • • . ... .... ... ... ...... ...... .. .... . ..... 
Teucrium nashil . ..... .... . ........... x ... ..... · -.. ... . ...... . - .... .. . ..... . ..... ± . ..... 
Phy MJiS vlSCOsa .. . .. ... ..... __ . ... . .. . X 
· 
... ... . 
--.. .... ... ... .. . ..... ...... X X .... .. 
'-'~~'. . - · .. . · - · · .. - .-. -
-
Epidermis. 
• 
Stomata. 
• , • , · ~ • .. • 0 ~ • • • il .- -j " , • '" 5~ • • Specloe. ~ · ~ -• • • • .. t:.; •• il • ~ , ;l • 0 .. 0 .~ ~ 0 i • • ~ •• ~, -- i~ • - - • ~~ " " • 0 -= , - · • 0 0 • ~ 0 ~ 0 - • ~ .!l 1" 1 - ! .0 ~ · • .. ~ Q • g ~ ~ • 3 .!l .!i ~ > 
'" 
., 
Panlcum amarum ..... ... ..... . ..... X .... .. . .. ... .. .... .. .... .. .. -- x x .... .. .. .... 
Mu hlen borgia. f!.llpea .......... ______ •. x .. .... . _ .... .. .... . ... .. 
-- .. --
X X -_ .. . - · ..... 
8par t ina patens ..... . ... . ...... ... --. x .. .... ...... --.... ...... . ..... X X . ..... 
--" " 
Spartina str icta .. ............ -- ...... . ..... x ...... ...... ...... -- .. .. x x -.. .. . . .. --. 
Chlori~ pet raea --. ...... .. -.. ... _ ..... .. ... . -- .... X .. .... X ...... ...... x _ .... - -..... 
'Unio;a p6D..cnlata .. .. .. _ ............ . x .. .... . .... . ...... .. .... . ..... x x ...... · ..... 
Yu<.:C8. aloitolia ...... ...... . .. .. •... ... X ..... . ...... I· .. · .. ...... X .. .... X . -- ... .. .... 
Yu",," gloriosa _ ..... ..... _ . ..... . ..... x .... .. . ..... x . ..... x ...... ...... , .. .... . ..... 
Myrlca. ca.rolinonsi8 . •.. " . . ..... ...... 
, 
X X , X ...... ...... 
.. .. .. 1-- ·· .. ...... ...... . ..... 
Myr ica. cem era .. .. . .. .... ..... . . ..... .. .... ...... x X ' ...... ...... . ..... ...... x . ..... 
Quereus virginiana ..... _ ............. .. .... ...... x x ...... .. .... ...... ...... X . ..... 
Zanthoxylum d av .. berculiH. .... .... ... ... ...... x x -- .... 
------
. ..... ...... X --.... 
Croton maritimua .... . .. ... ...... .... x ...... ...... .. .. .. x ...... .. .... . ..... .. .... x 
Ilex vomitoria ...... . --... -- ----...... .. .... ...... x ...... .. .... x .. .. .. · .. '" . ..... .. .... 
Oenothera hum"'- • .... ......... -.. x ...... ...... x x ... ... . ..... x ...... .. .... 
TC\lCf'ium naahlf __ .... __ ........... . . · .... - .. .... x x ...... .. .. -. . ..... . .. ... X .. .... I • P h yK&lls visootoa ..... ... ... x , ...... 
-.... ·1 ...... ...... .. .... · .. · .. 1···· .. \ .. · •• • ...... .. .... .. .... I 
~- ... -
- · 
I Bektn~ to the ~t :Ma.rah. Lu t i~ Inser ted herlO t ur convenience or cowptU"i80n with other 
GramiDeae. 

ANATOMY OF TRIGLOCHIN AND JUNCUS. 301 
SAI·T MARSH SPECIES. 
TRIGLOCHIN STRIATA Huiz & Pay. 
Leaf isolateral, thickish. 
Epidennis cells with llolllln<iulat,p walls, the outer strongly thiek· 
cned; clltide thick, granular; stomata. in rows parallel to the nerves, 
level with the surface, each borderpd hy 4 epidermal cells, of which 2 
are subsidiary and resemble the guar~l cells; hairs none. 
StereO'ly},e none. 
ChlO'renchyrna: Two outer layprs eompact, eOlltilluOUS on both SUl'­
faces, not palisadic except at tho leaf margius, whert~ :3 layers of pali ­
sade occur; parenchyma of t.he interior of the leaf containing little 
chlorophyll, interrupted by InClines. 
Jlestome bundles imbeddetl in the interior parenchyma, each sur­
rounded by a small-celled mestome sheath, whose inner walls are 
excessively thickened and layered; this surrounded by a sheath of 
large-celled, colorless parenehyma. 
SPARTINA STRICTA (Alt.) Roth. 
Treated for comparison among futnd-strand grasses, page 289. 
JUNCUS ROEllERIANUS Scheele. 
Lerrf vertical, teretc, sharp-pointed, stem-like. 
Epidermis cells all small, quadrangular (superficially), regular, 
without alternation of lohg and short cells; smaller and thicker-walled 
over Ute hands of chlorenchyma than over those of Bubepidermal 
stel'('ome, the outer walls much thickened and porous; stomata 1 with 
guard cells level with the other epidermal cells; hairs none. 
Stereome (suhepidermal) alternatillg with the chlorcnchyma in 
strong gronp!':!, whieh in cross sedion are I-shaped. 2 
Chlorenchyrna. of typical long, narrow palisade cells, mostly in 5 or 
6 layers . 
... "lIes/nuw unrulle.., anange<1 in several eoncentric eircles, com­
pletely surrounded hy steJ'eomo (whieh is parf,ieularly strong on the 
two i"'idcs parallel 1JO the leaf surface), the whole enveloped by a 
lWR1l1,ifully regular, large-celled parenchyma sheath. 'Vithin the 
8ter(~0ll1e the bunclln is cneirdcIl by a Jlwstome sheath of small, thick­
walled eells. The outer mcstome IHlIlIlh~s, with the colorless paren­
chyma between, f01'1I1 a eontinuous ring, unbroken by lacune~. The 
inner bundles lie in thin longitudinal plates of parenchyma, which 
separate large laclllles. Small hnndleK of stereome, each surrounded 
by a parenchyma sheath, also occur ill the interior of the leaf. 
Sfem differing but little from the Ipaf; differencp eotlsisting ehietJ.y 
in the presence of a eortex of some thiekness, and in the less elon­
gated chlorenchyma eells. 
---
IOf the type eommon in Juncaceap. Cyperaceae, and Gramineae. 
, .. I-fOrmige Triiger ., of t:;<:hWclluvllcr, 

ANATOMY m' \' INCJ<:'fOXICU~1 PALU81'RE. 303 
KO~TF,LETZKYA Vll{(HNtcA (L.) A. Gray . 
.l~e(ff broad nncl flat, hifadal, stclhtte-ptlhcseent on both surfaees. 
Epidermis r;ells with nOIlUlldulate, 1.hill walls, except ahove and 
he low t,he hl.f'tC'{,,1" veins, whel',,' t.lH~ (~lIt·icle is l'ather' thick and layered; 
stomata with guard Loci):'; slightl~' InHlninmlt, more numerous on the 
dorsal surface; hairs stellat,c, eOllsist, ill~ of 5 to 8 acut:e unicellular 
arm:-; with thick, smooth «1l1ticl(\ separate Ilearly 01' qllit,e to the base, 
etteh from a narrow foot cell ill flw t'pid e rmal plane. 
HlIPodernwl cullenchyma. stJ'ongly (leV0101l4.:<l a.bovu sud below the 
larJc r veins. 
Chlorellchym,,: Palisadc' 1-1ayel'ed; IHlClIUlrLtic tissue with Jlumer~ 
OUl~ small intercellular HlJlH~t IS; IHIl('ilage cavities distributed in the 
chl()l"enchYllla . 
• 
Jl[esl.mue Intnrlle.c; almost, ('omp~etl'-ly sUJ'l'ollluled by a thin, inter~ 
I'upt.ell sheath of stereullw, which is mo~t stI'ongly <levelopod out-side 
the leptollle. 
AMMANIA K()I<~H~EI Ht'itton, 
Leafflat, rather thin, al'Iu'oximatl'ly isolatel'al. 
Epiderrni8: Cell, with radial wall, 'trongly nndulate; all the walls 
thin, except nboye and helow the largel' veins, where the outm' walls 
arc considerably t, hicknll(~l ; elltieit' smooth; h)lirs none; stomata. 
chiefly pat'allel with thn ve ins, hutl some irregular; guard cells slightly 
prominent, each stoma. honic l'cd hy usually 4 undifferentiated epi· 
dermal cells. 
CoUenchyrrut Hone, 
Stereo'm.e none. • 
Chlorenchyrnn 11()I1log-ellecIlls, lIol, palisadic. 
VINUETUXICUM PALCHTlU': (PlIl'sh) A. fjray.1 
Lea1H~~ narrow, shal'ply I'elie:wu and hanJ.!ing a.lmost vertically, 
impet'feet!y isolntcntl. 
Epidermis: Cell walls rat IIVI" t.hi(~k, Ilot undula.te; cuticle wrinkled, 
eSI)ccially alJo\'t~ ami I )('Io\\' 1110 \'(~i Ill-i j :-;t.omnta more nu merODS on the 
ventral slll'fa( '~~, len·1 with t Iw ('l'itlC'l'llli:; , each bordered by 4 or (more 
often) 5 ordillal',\' ('l'ideJ'llli:-; (·.ells, generaH.\" panl,.llel with the leaf 
axis Oil tl ... n'IIII'al :->lIJ'factl, \ 'CI'r il'l'eg-ula.l'iy disposcd . often at right 
angles 10 till' axis 011 the dOI'sal slIr(aet'j hail's nOlle, 
H!J1)()d(~rlj/. a singlf', lHll'I'OW layor, only ahove the midrib. 
Colltmch!J11U1 nont'. 
Stereome. lIone. 
Chlorenchymn not, Jutlisadic. Iwmogeneons t.hrough the leaf, but 
t·ho interior containiug letis chlol'Uph,rll. 
Cells containing nuts.'oWs ()f crystals ((\H.!fliulil oxahtW) licattel'ed in 
the ehlorenchYJlla. 
Stem: Epidp.-r1ll i,<; as ill nil ' I(·af. 
. -_ .. _ -
----- -
I Sell/e,.u lila ,.il mut l)E;IC:-;ne. 
304 THE PLAN1' COVERINH OF OCRACOKE ISLAND. 
Hypoderm continuous, I-layered. Onter ('OI't.CX wit.h rathel' t,hiek­
walled cells, containing chlorophyll; inner COl't~x gradually heeomin~ 
thinner-walled "lid colorless. 
Slereome in a concentric lU!,.llu of isolated groups, lying inside 1.1)(' 
middle of the cortnx. 
Lnrf,ijPToUS duds few, lyiuJ.t just gll~ille the mestollH' hundles. 
• c. 
FlO. 4.7. -. U l'pin 1,,,rlijluJ'<I '- stomata a nd hail'H. 
a, Stomata on lflar: II , balr H.urlstoma. on ventral 
loot surface: c, hair on dorsal surface. Scale 
"0. 
Jlfesi.mne bundles hicoHa.(.('I'a.I , 
pe l'ilept,omat ie, tllt~ leptomc most.. 
14rongly d{J\'elopc(l Oil Ute onte l' 
periphery of Uw hadrolllo. 
LU'PIA ~OJHFLOHA 1tlx. 
JA-afl imperfectly bifacial, HSlI­
ally horizon t,al, 1mti sometimes 
vel,tical. 
"fi7jn:dermis alike 011 hoth sUI' ­
faeeH, cell walls thick , not undu­
late ; cuticle wrinkled; stomat.a 
(fig. 47) lying ill "II directions; 
guard cells almost level with the 
venkal surface, slightly depressed 
on the dorsal surface, cach stoma. 
bordered by 2 cres"ent -shapt>d , 
chlorophyll- holding, subsidiary 
cells which "re usually at right 
angles to but often " elirl.v or quite 
parall .. l to the gUll,,! i~lls, aud of 
which one is mmally (~onsiderably 
11l1'gel' than the ot.her; hnirsahun­
dnnt u" both f,,,,,*,, plt, ... llel to the 
ve ins, H.pprcssed, ly illJ,r in slight 
grooves of tlw epidermis, Dneh at.1Jaehed hy its middle (Iwnee 2-armerl) 
to a short cylindrical foot cell, whic'lI iii hOl'de recl by seve ral wedge ­
shaped (as seen from a.bove ) I'ad ially ILl'ranged epidermis eells, the 
free ce ll with a ve l'Y thic k, wmoty cut.icle. 
Hypodermal (:()ll fmchyma (not very tJ~'pieal), in 1 01' 2 laycrA a,hovo 
and ;3 01' 4 below the principal veins, illtel'l'upting the chlol'cnchymn. 
in full-grown leaves. 
Chlorenchymo: Palisuch~ 2-Ia.ytwet], Uw (01' 11:-; I'll-Ihel' SIHH"t; pne n­
matic t,iSSlHl l'nthl' " comp.wL, not, well d i fft.\l'cntial ,t.~d i'1'01Il t,lle palisade, 
hut it.s cell::; mOl't} nearly isodiamet,l'ie aut.! ('ontaillillg-lpss dllol'ophyJI . 
Meljionte bundles (of hu-geJ' ve ins) , wi t h SOIH O st"" ""HIII{! hclow tho 
leptome and a ~mRlt grotlv of eoHenchym3 above the hadJ'ome, wh ich 
finally becomes continuous with t,he subepide rmal group of col­
lenehymn, 
. --
I Compare Warming, Halofyt-Studier, p. 2:1:1, auil Solereder, S,st. Anat. , p. 71 3. 
• ANATOMY OF MONNIERA AND SOLIDAGO . 
.\ro~~·n~lU )TOXXIERA (T •. ) UH.ITT()~,I 
Occnrs in 2 fO!'IIlH; one ill Hhallow pools, largely suhmersed, with 
long stems, ololJgated internode:.;, and larger lea.ves; .t.he o1.lH'l' t(~l'l'I'S­
tl'hll, in wet sand, with short, eJ'ceping st ems, contracted internodel'\ 
and smaller leaves. 
(a) Aqnat ic forlll. Str'uctnl'c that of a partially suhlllPrsed hydl'O­
phyte, with t hin-walled tifoiR1WH, much roduced IIH ~StOI1l C system, no 
mechanical tissne, etc, 
Leaf isolat.,!',,!. 
Epidermic;: Cells with nndulate Int;el'n.1 walh~, tlw wnlls thhl exC'ept 
the mIter, whic h il'l somewhat; Ulickenpd j c uticle delicate-ly wrinkh.·<lj 
stomata morc Humorous on t he dor:-;al surface , gua.l'd cells about Im'e} 
with the epidermis, bordered hy 2 to 4 ordinary epidermal cells; hairs 
none. 
Cldorenchyma. homogcnC0 l18, palisado none. 
Meslome bundle .... · iJllmcd iat~~ly hol'del'e(l by chlol'tmchy ma" not. rHin~ 
forced by stereome or collenchyma. 
Stem: Epiderm.is as in tlw 10M. 
Cortical parenchyma in 1 or ~ ('ontinnons layers ju~t beneath the 
epidermis and around the (·cntm.l ('.rlinder, elsewhere ill l-laye l'(·(j 
plates, separating t,he lal'~c lac lIIH's. 
Jfestome cyliwlp1" eomposed of several bundles, inclosing a small 
qllHntity of pith. 
(b) Terrestria.l form. The only t.a.ngible differences from the aq uatic 
form are : StolOat.;" about Ctlually nnmerous on OOt,h leaf snrfa('CSi 
mestome bnn(lIcH somewha.t 1001'0 deve loped and walls of the vessels 
more lignified; mc~ophyll ~omcwhat mot'C compact. 
~OLIDA(i() SEMPF,RV1REXS L.2 
Leaf somewhat, fleHhy, Vt~ l·t ical nr nearly so, appl'oximately isolat· 
eral. 
Epidenn'i.'l: Cells with nOllllndlllate radial walls, only the ontm' 
strongly thickened, except abo\'(~ and below the large l' ve ins; cut,j oln 
strongly wrinkletl; stomata nnmerous on hoth faeNi wit.h guard cells 
level with tht! sUI'fact·, borde l"ed by 1Isually 4: o]'uiIll1l'j' epi(lc nnal ccll!-(j 
hai lOS none. 
Hypodermol ("oll()/l('hYillo in on ly I 01' 2 narrow laye rs a.boye and 
a Or 4 wide layers lido\\" 1 he larger veins. 
ChlorellchYIJ/.((. homogeneol1s, nOlle of it t~'pi('al palisau(l, freqnently 
interrupted, (Ispeeially oppo:-;it.C' til(' tn PstOlll(' b111HlI t.':o;, hy plat.cR of 
colorless, thin~wallt'd pal'(~ IIC : h.rma. (water t.isslle), which extend frolll 
t,he ventral t.o t.he aOl'S<~1 epidcl'mi:o;, alld ultima.tely break down iut.o 
lurge lacunes close heneath t.h t, ('pi<.ieJ"lIli!-' . 
--. . . .. __ ._--- . _----- .- -- - _ ... 
1 Herpesti.'f monnie'ra H . B. K, 
'The ml~terial examined was collpctet.l a.t Virginia Beach. Va. 
306 THE PLANT COYERING OF OCRACOKE ISLAND. 
Du,cf,s (prohahly resiniferous) nnmerOltB, especially near the dorsal 
surface, apparently always lying in the plates of water tissue, one 
below the leptmne of the mid vein. -
Jfes/,r)me bundles of the larger veins wit.h It narrow (in LI'RURHil'SP 
section crescent-slu\ped) gronp of comparatively t.hill-wa.lled ~tel'eOIlle 
above the had rome. t 
AHTER TENliIFOLI'LS L. 
Leaves narrow, almost vertical, isolatel'al, thick, with a (lcep gI'OOH.i 
on the dorsal surface on each :-;itle of the mid vein, ma.rgins slighUy 
incurved. 
Epiderml~": Cells comparatively large, walls not undulate, the outer 
greatly thickened; cuticle wrinklerl and with slight. furrows corre­
sponding t,O the radial walls of the cpiflcrmal cells; stoma1.a rather 
few and large, the gnard cells Hlightly sunken, mostly somewhat 
deflected in direction from that. of the 1eafaxis, U()f(]p)'ed h,r usually 
3 ordinary epidermis cells; hairs Hone. 
Hypodermal collellchyma ill a few narrow layers alJov~~ and rather 
wide layers below the midvein. 
Chlurp-nchynw consisting of palisade with high, 
about ::? layers on both fa.ces, strongly converging 
vein, espedally 011 the ventral side. 
lUtl'I'OW cells in , 
toward the mid-
Colorless parenchyma (water-st.orage tissue) occupying the interior 
of the leaf in small qnantity, and surrounding the mid vein, where it 
replaces the palisade. 
Mestome bundles not reinforced by stereome. 
ASTER HUBULATLTS Michx. 
Leaves wider and thilllwr than in the preeedillg, almost vertical, 
isolateral, flat, impressed above the milivein, ,,,hieh helow is promi­
nent, with a furrow on caeh side of it, 
Epidermis: Cell walls not undulate, thick, the outer vcry thiek, 
the innpl' eollenchymatiC':-t.hiC':kom·d where hypodp)'mal ('ollelleliyma 
occurs; cutiele wrinkled; stomat.a, with guard eolls lying parallel to 
the leaf axis, level with the ~mrfaee; hairs none. 
Hypod()rnwl (~()llnwhYIiI(t above and helowthe veim; (ahout 4 layol':'I 
between t.he leptome of tlHl midvein antI the dorsal epidcrmi:'l) and in 
Uw marginal angles. 
Uhlnf'endl!lma of compact palisade, occupying practica.lly tho entire 
thickness of the leaf except. whCl'o eollenchyma OCellI'S alHl ahout 1,} ... 
midvein. 
1 The leaves of nonmaritime species of Solidago (e. g., R. pciiola.ri.<.;, S. twylel'ia. 
and 8. erecta) exhibit some interesting difference~ from S. xI'mper-l'iI'CIIX. All three 
have bifacial leaves with cOtllpact, palisade and open pneumatic tissue (chloren, 
chyma least differentiated in .'.,', pctiohll'is). Stomata few (S. ('/'{'du, . ..,'. lIef/II'('la) 
or none (S, petiolul'i.'1) on the ventra.l Rurface, guard cells slightly prominent on 
the dorsal surfa.ce. Hairs along till' veins, especially Oil the dorsal face ill S. peliu­
laris, ~ or.t celled shsl'p-pt)illtell, uent. 
, 
• 
• 
ANATOMY OF BACCHARIS HALIMIFOLIA. 307 
Colorle~s ]Krrf'-neh!ltltft (wa.tel'-storage tissue) abo\"(' a.ml 011 eaeh ~ide 
of t,lw midvcill. 
Mes{,ollw lmlullf!.') witho1lt stel'eOIlH~ SUppOl'ttl, but, with It sma]) 
ular group of collonel1ynllt lying outsido the hatlrome. 1 
llACCHARIS HALIl\lll<'Or.1.\. r~. 
Leaves thickish, nearly nn'iieal, isolatl'l'al. 
• Irreg-
Epidermis: Cell wa.lls 1I0t, llndnlatp, thi(~kenet1, theouwl' ones greatly 
so; cuticle warty, especially on tho Ilol'sal surfa.ce; stomata IUOJ;Uy 
parallel to the \'oins, hut, wany somewhat de fl ect,ed, gllal'lL eells ~light1y 
prominent, ea.ch stoma radially hOI'(lel'etl hy -1 or 5 small epidermis 
celis. 
OollenchyrH([ (hypoderllllll) repla('i JIg' ('hlol'cnchyma above and lJelow 
the larger veins (fl UI' 7 layers below the leptome of the midve in), 
cOllt,a.ining no duets. '1 
Chlorerwh-yma: ]:»alisade O(~uupying- the whole thickncs~of t.ho leaf 
between the veins, nt' hoI' Ollell , espceially that in the int.erior of the leaf 
(but typical pneumati c tissue 11011('), eOTlvcl'ging t{)ward the midvein 
on the dorsal side; lal'",o, deep ail" (',liaml)e J's underneath the :-;t,Olllata. 
Colorless parenchYllln (water tiSSl((') ill '2 layers on ea('h side of the 
miuvein (cells circular ill CI'OSS :-;petion), in a single layer entirely sur­
rOlllllling' the Hmallcl' hlllHlI es. 
.- - -
I Three nonmaritime 8pt!Cies of Asrer were ~elec te<l for ('omparison with the two 
salt-marsh species: A. lmn·it·f:II.'1, a broad-leaved plant of IJoggy ground, a.nd A. 
dItTno~/I.'1 a.nd .. J. a;.f:oifit,x, IHlrruw-leave,l Sl)l.'cieli of dry, sandy soil. 
A. ericoitws ha.'i a prae tiea.lly isolateml leaf, epidermiR alike on both faces, with 
undulate radial au,l thickened outer walls. finely wrinkled cuticle. guard cel1s of 
the stomata. level with the vcntral surfa(;e, slightly prominent on the dorsa.l sur­
face; chlorenchyma. near buth surfaces compact uncl small-celled. more open and 
larg~r-cel1ea in the intt!rio r of t he leaf; hypodermal co llenchYllla in ~ layers above 
and Uclow the midvein; water 1'1l1'olichymH. Ilone. 
A. dl(llW.'W8 has a. distinctly hifacialleaf. t!pidcr1Di~ much H,ij in i' !. f'l' icohlc:!, but 
the 2 I'mrf)\Cffi mnrt-l c1lfferelltiated, the ventral with radial ceB walls ·less unaulate 
3Df} outor wall~ less thickellt.'ti than ill .: 1. eri('tlitif'I'I, cans larger and stomata lDuch 
fewer on the ventral s llrfac~, the dorsal with radial wallH more strongly undu­
late , a 11(1 !wattered, slew It!r, pointed. few-ct'lI6{l ha il'''; along the vein .... : paJi f'l'u.le com­
pad, pneumatic tissu,> OP(~ Il : veins "npportellllY h ypodermal collenchymatk tissne . 
• '1. /JII./IiCf.'II.'1 shows. of COIITse. the g-reatei'it amonnt of (l;tlerelt(~e from the $alt­
marsh forms. It ha .... a fiat, nppt'oxitllat('ly horizontal, ilifaoiallf'af. The veutrH.1 
eurfn('t~ i~ r ough with thick· walled, prickle-lilic, t ·celll'd hairs. mixed with scat­
t ered,longer, more slender. and thinner-walle(l hairs: the i'itomata Ii,", in all tHrec­
tions in aDd have their guard (!ella le\'el with tho dnl'sal s nrface. lm t an., wa11ting 
on the ventral face ; the c nticle is smooth; the chlor~DchyUla ill tlitfetentiate41 into 
a single layer of compact palisa,de anu a few layers of rather OIleD pneumatic tis· 
sue: no colorles~ pal'enehyma occurs inside the ei'i( lenll i~. 
On the whole the salt-marsh Asters show lOSH ull lltmoiclil divergence from inla.nd 
forms than does the salt-marsh Solidago. Of the two species, A. lenulJuliuH 
exhibits a more distillctivfl halophytic, or rather xerophytic, structure than does 
A. 8ubltlatu8. 
~ Warming, Halofyt-i::itudier , p. 19;), dCHCrihus duct!:! which occur in the collen­
chyma of the leaf ef Jjacchari.'1 dioica. 
308 THE PLANT COVERING OF OCRACOKE ISLAND. 
J,festolll p lJ undle,; with a strong gI'OHI' of stereomc only o1l1~~ide the 
hadromll in young leaves, ill older leaves a corresponding group of 
more ilUlllt'ro tls and ~malle J' c,011s out,side the leptome also. 
IVA FR{;TESCRSA 1 •. 1 
l.eaf thick , usnaHy almost v~~l'tical, Il(Iarly isolntoral. 
Epidn'ruis l.'f'll.o; small, walls not unduln.tc, thick, t1:-lpceially ttl(' 
ollter; cuticle wrinkh·d, espcdally abo\,t~ 
and helow tho veins; ~t,omata small, a..bont 
equally numerous OIl bot,h !-mrfaccs, the 
gna-rd cells sunken, pspccin.1ly on the dol'­
sal sUl'face, lying irregularly in all direc­
tionK; hairs 011 bot.h ""'faces (fig. 48) "p­
pressed, antrorse, thiek-walled, 2 or 3 
celled, sharp-pointed, t.he t" rmil",1 ,,.,11 
abruptly narrowed just above it~ base, 
nach hair horne upon 5 0(" G radia.lIy 
arranged foot cells which form a cushion 
that projects above t.lw level of the epide ,'­
mi s ; glands, 2 or 3 celled, sessile, nearly 
sphe ri(,Al, almost filling dop res.'iions in the 
epide rmis and rising slight ly above its g(\.n­
el"al level. 
FlO . fB. - lt,,(l !rutf'lict:1ll<-bair from 
ventralloat ~urrl\oo. Scale 3:l.I. 
Hypodermal colle/whyma 
groups above and helow the 
(abollt 10 I"ye ,.,. .. hove a",1 below the mid"ein) . 
in strong 
la.rgor veins 
Chlorew -hymfl pa.liHa(lic, in se\'(~ral laye rs, tho cells ~ma.n a.nd 
nRrI'OW, thoso .war tlw 10 id vein con ver:,{i 1Ig' toward i t j palisade fro­
que ntly illt'C J'J'lIpt,(~(1 «~spe(lin.l1y opposite thu nwstolll4~ bundles) by R 
few rOws of thin-wa1led, colorless pare nchyma (wat-c l" tissne), which 
ultimah!ly hrt'a.ks flnwn into Inc unes_ J.arge duc ts, eu.(~h Nurl'(mnded 
by n sheat.h or small 4 .. elhi, occm' in the wnt.el' tis~me, e~pccia.lly on the 
vent,ral sidn of the leaf. 
~festQrne bundles wit.h a little thin-wa.lled ~t,(H'(JO lUe oyor the 
hadl'omc,2 
~----~----------------. -------------
I The material examined was collected near Virginia. Beach . Virginia, 
t I va i m/)I' icata Walt. iI~ 8 common plant of the Atlantic sand Btrand in the 
Southeasteru States. although lIot observed upon Ocracoke Island. It presen ts 
some interesting llitferenc,'s from the salt·marsh 1. jl'ltfeSCCItI1, The leaves exam­
ined were collected near l'ape Henry. Virginia. 
The plant i!:l st1'ongly Rrl>m It :C. the leaf pe rfec tly isolatera,l, fleAhy and s ~ nootb. 
Epidcrmil.: celllj Hluch la rger ; cuticle not wrinkled : " ornata with guard ceUs 
level with the ventral snrruce, some what snnk('n on the dor:ml ; htlinJ 110118, 
Collf'Jlch!JlUfI less s trongly developed than in 1. jrlltesl·"l/.'I. 
Chlorellchyma consisting of :.! or a layl'1's of palisade on both surfaces. 
Colo'ricsH parench!Jma (water-storage tissue), filling the interior of the leaf aDd 
interrupting the palisade above and below all the veins, 
.1/f'.~fomf' fmll/ll~.'( lying in tbp mil)~t of the water -storage tisane: sten>ome n01)e. 
The lU()ijt important diffcreoces io I. imb,.;(~,,(( arc the tftroDIt de\'elollmeDt of 
• 

310 THE PLANT COVEUING OF OCRACOKE ISLAND. 
a companion cell and a hand of foul' or five cl'ibl'ile parenchyma 
cells. 1 
Leuf anatomy of ,~all~Jlutr .. ~h specieR. 
[The sign A illdkutel,\ prclSOlIce of ebaraeter: -.L it>! imperfect development.] 
.... --~--- _._ .. --_. 
Epidermis. 
Leaf_ -- -_.._- -----
.----~---
8peeio~. -
Cuticle. 
-] 
.. 
" .-~ 
" 
-
- -
•• ~. ~~ 
-- " ~=' 
Trhlluehinstriau •.... ______ .... ____ x ___ .____ X X __________ . X _________ _ 
Spa~tinastrietal _________ .1. ________ .. __ .•. ____ .... _____________________ .. __ ... 1. ______ ... ' .....• " .. 
JuncusroemsrianmL._._ .. I. ____ .J .. ______ X -••.••• - X _________ '11. ______________ . ___ _ 
Sa . . . I suvlUm mnrltunUIn _____ : ...... _. X ___ . __ ._ X X •••• _______________ . __ ." •• ___ _ 
Tissamn.rina. ___ ._ ..... _____ . ___ ._ X ........ X ______ .. ____ ' ••...•.. ___ .•.... X 
KostelotzkYUyirgillim ____ 
1 
~< ... _______ • ____ .. ____ .. _____________ • ___ ._ •• J _______ . __________ _ 
Ammaniakoehllei .... ___ . __ ._._. ± ________ . __ •. ________ . ____ .•• ___ •. ..!._________ X 
Vincetoxicumpalll:-;trt' __ .J.______ ± ______ ••• _______ X X '- __ •••.. __ ..•••• _._. 
Lippianodiflorn ____ ._..... ± .... _._ •••• __ •• _ ________ x x ___ . ______ .• _____ . __ 
- - ' MOIlDlora monnwru _______ !. ______ _ x 
IvafrutoBcellB . ________________ .... x 
Solidago sempervil'ens _ _ _ _ _ _ _ _ _ _ _ _ ± 
Astertonuitolius. __ .... _._ ... _.... X 
Aster HuLulatlls ______ ._._. '. ___ ... 
Baccharis halimifoliu ______ ! . ____ .. _ 
x 
x 
• __ A _______ A • _______ •• _. __ 
_ .. _._.-
x 
x 
x 
----.-.. ---- ._--
x 
x 
x 
x 
x 
x x 
x 
---.. _---- ----------
x ._-_.- ---- '-'-.-,,--
x 
---------- ----------
x _. __ ._._ .. ---.------
._ ... _---- x -----_. __ . 
Borrichiafrute8Cens . __ .• ___ . __ ._. ± 
._----_. 
x 
x 
--_._---_. ---------- ---_._---- ----------
-'--- ---' -- ---'-' '- - --'---
J ChnracttlrS giYen under species of the" sand strand," ]mge 289, 
- - -.- .... --.-~--
--------------
1 BO'rrichia al'lJorescclI,,( (compare Warming, Halot'yt-Studier, p_ 212) is a very 
gimilar but larger plant of the tropical American strand, It differs from B.frlde,~­
cens in the fonowing particulars, the charaoters being taken from material col­
lected in South Florida and Porto Rico: 
Hairs much thicker· walled, entirely disappearing in old (more than 1 year 
old?) leaves; stomata on hoth surt'ace8, with guard ('.ells slightly promineut on the 
ventral face, less numerous and with guard colIs slightly sunken on the dorsal 
face; epidel'mal cell walls, especially the outer. thick; palisade interrupted both 
above and below hy extensions of the water-storage tissue. which on the ventral 
side ultimately disorganize and form large lacunes; hypodermal collenchyma 
occurring where the palisade is interrupted on the ventral side; colienchyma 
taking the place of stereome as supports of the veins. especially strong on the lep­
tome side. 
From Warming's deseriptioll and figure of B. a'rbori~seells my specimens showed 
important differences: (1) The presence of hairs (. elsewhere in the same paller 
Warming meutioll:-! their occurrence ill this 8pecies); (2) Htomata with guard cells 
slightly prominent on the ventral surface (Warming writes" :stomata sunken"); 
(3) collenchyma present and strongly developed: (4) mestolll8 bundles in three 
planes (one according to Warming), some small ones being:sitllated near the upper 
and the lower epidermis, while the midvein i8 central in the watel'-storage tissue. 
; 
• 
, 
f 
• 
ANATmlICAL SUMlIARY OF SALT-MARSH SPECIES. 311 
Leaf cmatomy (if ,'jult·mar:>/i '~JJccie.'j-( 'ont.inllt'd. 
[The sign x huHcH.tc~ p}'f.~llnl or e baral'tk.r : ,. i~ impc r fnc t dcvd" IJuumt.] 
_ .. ' ,- - -
I 
... - - -
• 
- -. -.-
SpodUfl. 
- "-- -'-' 
'rriglodlin IJtrh~tl~ . __ .. _ ... x .. . . ... . 1. .. .. .. 
Stomata. 
• 
-
• • 
= 
.­
-
1 
-...... -
• 
-= 
• 
• 
o 
o 
.. 
= 
• :./:; 
' ....... . 
• 
• 
-
'" o 
.. oJ: 
n 
t 
-
x • ••••••• x 
, . I' :-;part1nn~tr ,~ta ----·· ··· ·i ···· -··· .... ... . ......... ...... .. --- .... ..... .... -..... - ····-·-·1··---· ·· 
J\iIlCll>-lrvelllel'ianu~ . . .... : .... .. .. : . . . . .... . ........ . . .. .•• . x :"" "", X • •• ; ••• 1 ...... •• 
Se~u\'ium maritimulIl . . .. . ;< • . . . ••• • . . . . ..•• "" " " ,' ;.; • .•.... . ---- - .. . 1'_' _"" 
•. , ., 1 
Tu;.--,nIlUirnUl --- - -- ..... 1. . .. -- -- . .... • -. .. .. ... . .'. . -- --- . . .•..... • :.: , ••• • -.-.1' ... -- .. KO~ltell;ltzkyl\ virginica ... ! >< ... .•••• • •. .... ..1 :, ..... .. ........ _ ....... ___ ._ ..... _ ..
I I 1 :-:; .. , Ammania koehllei """ "1 
ViDf'etoxicum pulu.'Itre . . . 
Lippitt. lIudiftora . ...... . ... ' 
, 
, 
• 
x 
Monniera mODni~ru"" " ' 1 x 
Ivl!. rrllte~",I . . . ____ ...... : ? 
: ~: : ::::[:: ::::: ........... :" ' I ~ :: :.: ::: . -.... ..1 :::: :::: 
-- -- ---- .. .. ---- ... .. .. __ . , : .. . 1 ____ __ 1 X 
.. ...... ... -.. .. ....... . ] -- 1' ·· · .. ··1 ··· · " ' 1" ':" 
.. .. ... . .. . ___ . . . . . . . .. . ~ __ . _.. .. . x 
· . _ ..... 
· .. _.-.. 
-- - " '" 
.. . _ .... 
, 
'-_ ., . ... . . . __ .---
· -..... . · ...... . 
........ 
.. _ . .... 
.. .. : .. .... .. ·r -.. -.. 
.. . .. ....... _- -. 
Solidago !lemlX~r\·irells .. ", i ;.: 
A!jh~l' tenuifol1u>-l _____ . .• •• 1 , ', 
.. . ... ... 
1 A !;tel' s~hulatus: ... : .. . ... 1 ;.: · . .... . . ... . . _- - . . . . . . . .' . ... .. ... . . . . .... . .. . .. . . 
, 1 Bacclmrls lIa11011( .. 11II . .... :-: · . ' ... , : ::1' ;' , .... ........ . ... ... . 1 BI ,rridlia f rut tlSCt'ns . . .... 1 . . .. ... . ... . ... . 1" -.. ... . 
Spades. 
= 
• 
" -
--
-
-0 , 
, 
Epidl·!·mllj. 
Hair~. 
-
-
• 
-• 
-.
-• 
----- -
• ~ 
•• ~ 
- - - - - -=- -- ---
Triglochin strill-tll __ . . .. : . . . .. .1. ... _.:_ ..... ... .. _ 
<5 00 ;; 
- [.- -
8 . . t ' partum ,..trw" ___ .... 
JUlien:> r oom o.: r ialluI'I 
S (''''11 vi 111ll III1U'j t I III n III _ 
TiH>l:t mari lltl 
~' lSt ,.J6tz" ra d q:inic'a 
,\mnItHlin kHe llilo i __ _ 
· ..... 
· .. ... 
· . . . . . 
-.... . 
· -.... 
Vincetox:cu m ptIoillst.rl! ..... _ 
L ' . · .. "ff ' lppll.l.n .. . .. 1 ora . ___ .... :, 
Monniera. mODlliera ... I ... .. . 
, Iva frutesceus . __ ... __ . . 
SolJdagosempervircU8 I 
Aster tenuitolius .. _ .. . . 
" 
• •• •• 
. . . .. 
-.... . 
-... .. ...... _··· ··· 1· .. ... .. .... -" "" ' j"" " .. ... . 
· ..... ... ... . - -y - .... ... .. ... . . --... - ... .. 
.. · . . . .. .. .... ..... . .... .. ... -_ .. .. .. . -- -_ ... . ... . 
- ..... .. .... ..... . . . . .. . .' . 
-..... · .. .. .... .. -_ . .. . ;.'. 1 _ ••• , • . . .. . . . .' . · ... .. 
• • • • • • . ... - - . . . . . . ... .. . · ... .. 
.. _--- -- . -- . ...... - . ... . 
. ----_ .... .. . · ..... ' .. _--- ... .. . 
I 
-- ----
.... - - - - . . .. 
· . . .. . 
, 
, 
· . .. . . .. .. . ' I ... -_ . 
· ..... 
--:--1-.... ·1------ , .. : .. 
• • • . . .... ... ..... '. 
· . - - -- . . .. - - -- - .. .. .. . . .. ........ .. . .... . ..... . 
• •••• • · .... . · . .. . . .... .. . . ... . . .. .. . . .... . . .... _ . .... . 
! 
Hypoder· 
mal collen · 
, bl·mn. o r 
col eochy · 
matic ti~lIu. 
.'l 
1 . 
... 
o.!l 
• 
.. -
-• o 
- -
.._--_ ... ... . 
· . . . .. . . .... . 
. . ..... . ' --" 
.. ....... - ... . 
· . . . . . 
-- .. .. -
· .... . -
x 
... -- .. 
, 
-- .. .. 
I. ... . 
._ .... 
. ... _. 
--_. -. 
..... . 
· ... .. . , 
, 
· . -- ... 
• 
· - ... . 
Aster8ubulntu8 ...... . ... .. . .. . . , - .. .. ... . . . -_ ... , ... ... ' ...... . . .. ..... .... - x 
Baccharis balimifolia .. ! ... ... ' ... , .. .. ... . 
Borrichia. frutesceDs _ .. ! X 
, 
, 1 
· ~ !-:::J '-;":";" :::: :: .::::: :::::: ...... .. -- .. 
, 
· ..... 
· .. .. . 
I Characters gi ven \Iml~ ' r :\»odes of tbe " t;lI.lld straD~l. " Vl'b"8 2811. 
• 
312 THE PLANT COn;RING OF OCRACOKE ISLAND. 
--------- --
Sten"HW'. ( ~hlnr( 'Il (. h yul!t. 
--- .. 
0 , ",< 
s BF 
c . ,. • ::.0 ~ ~ 
• ~ •• • o . .-, a~ • I .c - • " " 
• 
• ~ .0 
• •• 0 0 8 .. 
--
~. c , 
" 
0 ~ , c , • • ? • .,c • I .- ~ • • 
, 
-0 CO C ~ -
" 
a 0 • 0 o· , .- .::: • I ,,0 ~ 0 -•• 
-
c 
• • .~ , ~~ ~ • ., -11 0 0 8 0 , ;.:::::~ 
-
.~ 
" 
I 
" 
0 .. .~ 0 c •• T. 
-< 
" " 
'- '-.., • 
--
-- ----- - ---
_. 
~ 
c 
• ~" 1-0::: 
:to 1-0 
'" a ":::: 9= 
-
'" 
, , 
" 
, 
"" 
, 
· -
, 
• • --~ 
.. I 
c. I 
Water 
JlfLrl~ll­
chyma. 
~ , 0 
-
-
.0 • 
• ~. 
- • -•• , c-
• , ~"" 
" 
, 
.• c
..,....; , §..s c. 
.• 0 
- ~o 
' . 08 ::.0 
~~ ::..S 
c ". 
--
o. 
-- :as •• 
.. , 0 
Triglochin.~tria.tlL_ ...• ______ '. ____ . __ .. __ \: . _____ . ________ .......... _ ... 0 ____ _ 
Mestomo 
bundles. 
._-----
• I < ~ 8 < , 0 , ~ 
.0 
'.c 
• 
• 
, o . 
8 I c-" ~ 
0 I ~~ ~ 
• 
, 
• .0 ,
A' 8 
.0 .0 
~ ~ 
., 
--~ ,~ 
x x 
, , . I S}lartinR 8tl'it:ta 1 ....... _____ .: ._ .... _____ .' ___ "._: + ____ •• _____ . ____ • ___ • __ • _____ ,". _ • ______ •• __ •••••• 
J . ,.: X" x" x x unl'us r()(·ln(~rlanU8_.. .., ______. _, _____ . ---.-. _+ __ ._ ••••••.•••• __ , 
, 
St'!<twiummaritimuIn .. ___ ... :. ___ .. __ ... , '.: ______ .. ___ ••• ___ ..... ____ ._~. __ . ____ .•.•....... 
Tissn.marim~ ........•••. - .... 1 ...... : ....... ~.; :-··~··:···~··i······I······ :>; 1,--,-, -------1- .... . 
KosteletzkYll.drgirlica_ ••. _._ ._ .. __ 1 ;< .•• _ •• xl:>; ................... _. __ .. ______ .•••.•• 
Ammania koe1l1lei - ____ - - .... ' ...... 1. -.--. ~~ .. -.. -. -- .-.-: ...... I .. -.-.1- -.. -- .- .. _.1_ .•.• _. i- --'" 
Vincetoxicnmpalustre __ ._ .. 1 _____ . 1 ____ ._ .', ______ ..... _ •••••• _____ .' •••• _. _ ••••• ,._ ••• _. ___ ••• 
LiPllilLlloclifiora ........ ________ .. __ ' x .... __ r .+ i x ; .... -.1 ....... ___ ._ ...... !._. ____ ..... . 
MOlluieramolluiera. __ .. __ .•.. _ .... 1 __ •••• x 1--- ... 1---.--.- .. -.. _. ______ .. __ ... _.1._ •..•• _ ... .. 
, 
x i-- ... -_ ... _.1 x IvatrutesceIl1'l_ .......... __ ._ .. _._ . .' x 
x . __ . __ ._____ x 
•• . , 
._._-- -_. __ . 
._-_ .. - ..... . 
x . __ ._-- ------SolidllgosBIIIJlI~rvirlllls_ ------ ------i x 
Aster l:enuiroliuH __ ._. __ -.-.- ..... T ... -. x x x x ....... _- .... -_.-.. 
Aster sulmlutus_ .. ___ .. __ .. _. ___ . ____ .• _. x ,.-.... X i ...... - .. --..... 
X '._ ......... _, ...... x __ . __ . Baccharis halimifolin .. _ ••••• _ ..... x 
. __ ._-- _._---
. __ ._ .. "-_._--
; 
x x j--"" -------1------
'--'-
Borriehiat'rutoHelms .. _ ...... _ ••. _. " 1 X A , x 
I Characters given under ~pe('j('" of the" nund "h'and," ]). 289. 
GEOGRAPHICAL AFFINITIES OF THE FLORA. 
AecoHling to it.s geographie position, Oel'aeoke Island lies well 
within the Austl'ol'ipaJ'ian area of t.he J.ower Anstrallife zone in North 
America. l For two reasonA, however, this relatiollship of its flora is 
somewhat obscured: (1) By the large pI'oportion of strand species, 
many of which have a very extensive gpographie range; and (2) by the 
absence of many of the most chal'actl'rhitic species of the Austro­
ripariull area, (hw to thH peculiar physieal ell virOlllllent. 
Of tho t"ta) numb,,,. of species of em b''Y0phyt.cs (about. 1 ;)5) collected 
or observed upon Ocracoke Island, between Due-fourth ana onc-third 
may be designat,(\d as maritime, i. e., normally occlIlTing' ollly in t.he 
salt! mal'siws 01' on the salld sLl'and hOl'<lt'J'ing" t,he ocean. These may 
he segregat,ed into -1 groups, accol'uillg 10 geogl'aphieaIl'ange: 
]. Speeics ocenrring also on Ute c()ast.~ of t J'opieal America. 
A prcfixed asterisk (*) indicat.es thai; Ute sPlwies does HOt ext·end 
nOJ,th of Ute month of Chesapeake Bay j a pndixed dagger (t) that 
the northern limit is in North Carolina, pl'Obably noti far frolll Oel'a­
cokt~. Triyluchin ~t,.iata and 3[rrnniera. 1w)/wiera extend north to 
pastern Man·lalili . 
• 
_ ... _ ... -
- .. --~-~--~ -
1 Merriam, Heogr. Dist.rih. p. 211; Life Znnes p. 4i), map. 
• 
. 
• 
• 
GEOGRAPHICAL AF~'INITIES OF THE ~'LORA. 313 
7'riaifJe/tin , .. tria/It R. & P. 
*Quercus virginiana L,' 
teMoris petraea Sw. 
*l;,tiola l)(uticulata L. 
* FimbriatyUs sp(ulicert Yah!. 
t Yucca aloifolia L. 
if- Physalis t-i.'icosa L. 
Mmmiera 11lollniera H. B. K. 
.. Borricltia jrlttesceng L. 
tlpmnoea sagittala Cay. 
2. Species mo.;tly or cntir-ely confincd to the seacoast of the Austro­
riparian area: Zautlw.rylll1n clavlt-7wrr~ulis and, possibly, Ile:x,t'o1n'i­
laria extend northward tu Virginia, while the rest att.ain their northern 
limit in North Carnlina. 
Mllhlenbergia filipf~!~ M. A. Curtis. 
rucca glor;osa L. 
Croton 11I,aritimwt WaJt. 
Zanthoxulum clava-herculis L. 
[lex vomitoria Ait. 
Opuntia pe.'f-corui Le Conte. 
Vincetoxicumpalustre (Pursh) A.Gray. 
3. Spedcs l'Onfined to the Atlant.ic seltCOa'lt of N ortb America and 
ranging Ilort,h of tho Austroriparian area. The northern limit of 
eacb i8 cited as given in Britt.on & Brown's Illustrated Flora. 
Panicum amarum minus Vasey & 
Scribn. (Conne<:ticut). 
SparUtza pateuH (Ait.) Muhl. (Nova 
Scotia). 
Distichlis spicaict (L.) Gr&ene~ (Maine). 
Juncu8 rbemerianWf Scheele (New Jer­
sey). 
Se.'Hwimn maritimum (Walt.) B. S. P . 
(New York) . 
Euphurbia polygon'ijolia L. (Rhode 
Island). 
Kostektzkya virginica L. (New York). 
Ammania koehnei Britton (New Jersey) . 
Oenothera humijusa Nutt. (New Jer­
s.y), 
Li71lonium carQlim'anum, (Muhl.) Brit ­
ton (Labrador). 
Iva jrutescens L. (Massuchllsetts). 
Solidago 8elnpervire1ts L . (New Bruns­
wick). 
Aster tenuijolilul L. (Massachusetts). 
Asier $Ubtdatus Mich:l. (New Ham); 
shire). 
Baccharis 
setta). 
halimijolia L. (M8B88chu-
4. SpecieH oecurring a.lso on the ~(!a.coa....,,;t of the 1101'1 hnrn hemisphere 
in the OM World. 
Spartina 8trict(j. (Ait.) Roth. 
Alriplex lIuxiala L. 
Sulicornia hCI'i.Hlcea L. 
SalHola kali L. 
Tissa marina (L.) Britton. 
Of t,he nonmlLl'itimu species of the islanc1, tiftE'en are introduced 
aud aro chiefly weeds of American orlgin. Tho remaincl4~r (about 
two-thirds of the total flol'a) illclmlt)H several mainly tropical species, 
such a," Lippi(/. no<iijlOl'a ~[jchx., Cen/eUa asiat-ica (L.) U rb"tl, Purie/",­
ria debilis Forst. , and Til/uni..lsin u.'meuides L., which, while hardly mari­
time, arc found usually lwar the sen,coast in the Anstroriparian arca. 
Finally, after excluding all the pl'cccflingcat,egori(~8except the second 
of strand plants, we have" list of species among wbicb the Austro­
riparian element is sntliciently predominant to leave no q ucstion as 
to the general affinity of t.he flora. 
As previously remarked, however, many of the plants most char-
--- -- - -- -.---~.:-
I Normally a atmnl) plant in Virginia. a.nd North Carolina. 
~ The typical form, 
314 THE PLANT COVERING OF OCHACOKJ> ISLAND. 
acterist,ic of the whole AURtroripal'ian area, and abundant on the 
mainln,nd, ~mlol ''''''ely 30 kilometers (list,ant, a.re wanting upon Ocracoke 
Island. N otnhle among these nbsentees are tho pines (Piuus 1'al/1.s1 J'is, 
P. kulda), tho gUllls (Nyssa .pp.), tho hald cyp"eHs (1lu')I/.:Il11t "i8-
tichu'm), t,he deciduous oa.ks, the Cfl-no (A"I'U1ulinarin IIULCl'o."il}et"lIlrt), 
species of Erianthus, Car(~ .. r, /,'el'I'IlCOSll, Smila.r. 7((u1"I/olia, and Bl)J' ­
chernia scanden .. o.;. ] lal"d ly lc8M striking iii t·he nOnOOCUl'('c nCe of 1I10st of 
the bright-flowered heru!i thut aboll.D41 in tho pine forests on {,he west 
shore of Pamlico Sound. Such arc species of Coreopsis, Helianthl1s, 
Lacinaria (Liat.'is), Eupatorium, Solidago, Rhexia, Get'ardia, IIypel'­
icurn, Sarracenia, Ha.benaria, and !'olygala. Tho ullfavorableeuyiroll ­
ment is douhtless responsible for the absenee of many of these plants, 
conditions upon the island being suitablo only to the hnl'diest species, 
Scarcity of shade, of humU!:~, a.lld uf fl'tY.:Jh water a.m!Hunts in like mau­
ner for the poverty of tho flora. in most of tho lowe I' forms, such as 
fresh-wateralgll,u, fungi, hepA.ticae, mo~scs, and fcrus, The numorOllS 
arrangem<;nts hy which lIl"nyof the highN' plants are protect"d against 
excessive lOBS of water may also ~erve iu somo llleaSlll't~ for Vl'otection 
against parasitic leaf fungi, and may partly account for the COIll ­
parative scarcity of the lattel·. 
The general "spect. of the plant covering is not attractive. Bright 
green foliage and flowers of brilliant coloring arc too l'3cal'ce to make 
much impression, while, except in the salt lIuu'sh(>.s, the plants al'o 
usually so scattered that it is the soil which gives toll" to the I .. Ild­
scape. Furthermore, the trees and shruus are most.ly chal'aetcl'i7.ed 
by gnarled tl'unks, many dead branches. and I'a.g~ed foliug-e, a.s a 
result of ~xposure to Ma.ud-hulen winds, Altogether, tho picture iM 
one of somber monotony, 
LIST OF PLAlITS COLLECTED AI!ID OBSERVED. 
rThe prel1xed tUIoterisk donow~ that tuo pll\nt II:! Intrvduwd.J 
LICHENES. 
Ullnea burba-ta L. 
Ramalina montagnei De Noi, 
]l(USCL 
Bryu1/I,. argenteum L, 
Rhynchosteg-ium serrulatum Hedw. 
POLYPODIACEAE. 
Asplenium, platyneurvn (L.) Oakes. (A, cbe'/.eU1n. Att.) 
PINACEAE 
Juniperus virginiana L, 
TYPHACEAE. 
Typha latijalia L. 
SCHEUCHZERlACEAE. 
Triglochin striata Ruiz & Pav, 
• 
, 
LIST OF SPECIES. 
POACEAE. 
Andropogon glO1neratu8 (Walt.) B. S. P. (A. 1na(:ronru."l Micbx., 
Pw;palum ciliatijoi"iu11l. Micbx. 
Paspalnffl disticliU'IIt L. 
Paspalum laeve M leb:=<o 
Syntherilfma fimbriata (Smith) N 8sh. (Digitaria jimbriata Smith.) 
Panieum amarum 'minus Vasey & Scribner. 
Panicm1l. la1lttginoslt1n Ell. (?) 
Panicuru laxiflorum I.am. 
Panicu7iL neuranthmn Griaeb. 
Paniclt1n wulteri PUl'8h. 
OplillmelHtS ~'tariu~ (Lam.) Roem. & Schult. 
315 
Cltaetodtloo -illlberbis pereuuis (Hall) Scribn. & MerriU. (C. 1ICr.'Ji(';oinr 
Bicknell. ) 
Humaloccnchrus virginieu.1J (Wi]](l. ) Britton. (Leerxia V'irgirdcft WiI1d.) 
M1thlc1Ibcrgiu filipe8 ld. A. Curtis. 
*Sporol,olusind-icus (L. ) R. Dr. 
*Capriola duetylon (L.) Kuntze. (Cgl/odon dact,l/lon Pera.) 
Spartina patens (Ait.) Muhl, (S. iU1Hwa Ell. ) 
Spartina flt ricta (Ait.) Roth. 
Chloris petraea Sw. 
*Eleusine i'ndica (L.) Gaertn. 
Triplasis purpurea (Walt.) Chapw. 
EragrulJtis nitida (Ell.) Chapw. 
Uniola laxa (L.) B. S. P . . (U. g'racili.'I Michx.) 
Uniula paniculatu L. 
I>i&Uc/;li8 spicata (L.) GreenE!. (D. ntaritima Raf.) 
CYPERACEAE. 
Cyperm cylindric1ls (Ell.) Britton. (C. torreyi Britton.) 
Cyperus cchinatu8 (Ell.) \Vood. (C. baldwinii Torr.) 
Cyperus n'uttallii Eddy. 
Cyperus speeio8Us Vahl. 
E/rocharis Bp. 
Die/;rolluma colorata (L.) A. S. Hitchcock. (D. leueooephala Micbx.) 
FimlJri:'ItylilJ Hpadicea (L.) V u.bI. 
ScirpllH amcricanu8 Pers. (S.}JUugenlJ Vahl.) 
Sc{(ria verticil/ata MuM. 
Cladium effwmm Torr. 
ARACEAE. 
Acot'U.'I calanUlx L. 
BROMELIACEAE. 
Tilla'1lflsia '/I,'meoidex L. 
JUNCACEAE. 
Junc1ts dichotomu.'I Ell. 
Junett.~ roemerianus Scheele. 
Jut/cus sC'irpoides Lam. 
Hu,'Cu aloi/olia L. 
Yucca glorWsa L. 
LILIACEAE. 
BMILACEAE. 
Sm.ilax bona-n(J.i.~ L . (S. fmll./loid"s A. Gray.) 
• 
316 THE PLANT COVERING OF OCRACOKE ISLAND. 
Myrica carolinew>liH Mill. 
Myrica cerifera L. 
FAGACEAE. 
Quercus virgin-iana L. (Q. virens Ait.) 
lII[ORACEAE 
* Ficus carica L. 
* Brotl8BOnetia papyri/era (L.) Vent. 
URTICACEAE. 
Parieturia dehilis Forst. 
POLYGONACEAE 
Polygonum punctatnrn Ell. 
Rumexsp. 
CHENOPODIACEAE. 
·Ohenopodium anthelminticum L. 
Atrip!e.x hastata L. 
Salicornia herbacea L. 
Salsola kali L. 
l'HX·rOLACCACEAE. 
• Phytolacea decandra L. ' 
AIZOACEAE. 
Sesuvium maritimum (Walt.) B. S. P. (S. pentandrum Ell) 
Mollugo verticillata L. • 
ALSINACEAE. 
Tissa marina (L.) Britton. (Spergularia salina J. & C. Presl.) 
ROSACEAE. 
Rubus trivialis Micbx. 
CAElIAI.PIN ACE AE. 
* Cassia occidentalis L. 
VICIACEAE. 
Aeschynomene virginica (L.) B. S. P. (A.lti.'pida Willd.) 
Meibomia paniculata (L.) Kuntze. (Desmodium paniculatum DC.) 
Galactia volubil .. (L.) Britton. (G. pilosa Ell.) 
LINACEAE. 
Unum medium (Planch.) Britton. 
RUTACEAE. 
Zanthoxylum clavaahereuli.'f L. 
EUPHOBBIACEAE 
Croton maritimus Walt. 
-d,('nlllpha gracilens A. Gray. 
Euphorbia polygonifolia L. 
ANACABDIACEAE. 
Rhus radicans L. 
• 
• 
• 
• 
• 
LIST OF SPECIES. 
Ilea; glabra (L.) A. Gray. 
Ilex opaca Ait. 
ILlCACEAE 
flex vcnnitoriu Ait. (I. cassine Walt.) 
VlTACEAE. 
Vitis aestioo./;is Micb~. 
Jl[ALV ACEAE. 
Kosteletzkya 1Jirgim:ea (L. ) A. Gray. 
Hibiscu., moscheutuN L. 
* Gossypium herbaceurn L . 
RYPERICACEAB. 
Ascyrum hypericoide,'J L. 
CISTACEAE. 
Lechea tJillosa Ell. (L. nurjQr Miell. ) 
CACTACEAE. 
Opuntia pea.corvi La Conte. 
LYTRRACEAE 
A1nmania koehnei Britt. 
ON AGRACE Ali:. 
Ludwigia alala Ell. 
Ludwigia microcarpa Micbx. 
Oenothera humifusa Nutt . 
APIACEAB. 
Sanicula 8p. 
Hydroootyle umoollata L. 
Oentella asiaticc (L.) UriJ8n. 
PRIJl[ULACEAE. 
Samolus flaribundus H. B. K. 
PLUlIIBAGINACE'E. 
317 
• 
Limoniu,nt carolinianmn (Walt.) Britton. (Statice liflwnium vaT. carolini-­
anum A. Gray.) 
LOGANIACEAE. 
Cyllnctmmm m'hreoin (L.) Britton. (Mitremu lJetiolata Torr. & Gr.) 
PolyprctnU1n prvcumbeux L. 
ABCLEPIADACEAE. 
Vincetoxicu.rnpalu,'drf~ (Purah) A. GrIlY. (Seutera mariti1na Doone.) 
CONVOLVULACEAE. 
Ip<nnoea sugittata Cav. 
Lippia nodiftora Michx. 
Cqllicarpa amer«;<l1ut L. 
VERBENACEAE. 
3\8 
• 
THE PLANT COVERING OF OCRACOKE ISLAND. 
NEPETACll"B . 
Teucrium nashii Kearney. 
Monarda punctata L. 
Physalis m.co.a L. 
Solanum carolinenae L. 
• Sola1l11.m nigrum L. 
SOT.A NACBAB. 
• Lyeopersicum esculentum L. 
• Datura. tatuZa L. 
. BCROPB0 LARIACEAB. 
• Verba,cum thapR1t.R L. 
Monniera monniera (L.) Britton. (Herpe&ti.'f tIlonniera H. B. K.) 
Gerardia maritima Raf. 
ROBIAClEAB. 
Oldenlandia unijlora L. (0. glomerata Michx.) 
Diodia teres Walt. 
Diodia t1irginiana L. 
Galium 8p. (probably G. tinctorium L. or G. clay toni Michx.). 
CUOORBITACBAB 
• Citrullus mdgaris Behre.d. 
Melothria pendula L. 
CICBORIACEAE 
Hieraoium gronovii L. 
CARDUAOBAB. 
Elephantopus nudatu.~ A. Gray. 
Mikania 3Ctlnderu~ (L.) WiUd. 
Solidago semperoirens L. 
Euthamia caroliniana (L.) Greene. (Solidago tenuifolia Purah.) 
ARter saliei!oliu8 Lam. var. 
Aster subulatu8 Michx. 
Aster tenuifolius L. 
Erigeron canadenxV! L. 
Baccharis halimifolia L. 
Pluchea camphora!a (L.) DC. 
PlueJaeajoeti<ia (L.) B. S. P. (P. l>ijro ... DC.) 
GlIapllCllium purpuremn L. 
Ambrosia artemisiaejolia L. 
Iva jrute.~ceIl8 L . 
XanthiuUl sp. 
Xanthiu", sp. 
Borrichia jrute&'(,-lls L. 
• Biden. bipimluta L, 
Ereehtite8 hieracifolict (L.) Raf. 
Oarduu~ spinosissimu8 Walt. (CniC'lt81wTriduiIl8 Punh.) 
• 
WORr:s REFERRED TO. 319 
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o 
. 
•