. . . 
• 
THE PLANT LIFE OF ELLIS, GREAT, LITTLE, AND 
LONG LAKES IN NORTH CAROLINA . 
• 
By WILLIAM n. BROWN. 
IlITRODUCTION. 
The study of the flora of Ellis, Great, Little, and Long lakes, North 
Carolina, was carried on from the United States Fisheries Laboratory 
at Beaufort, in that State, during the summer of 1908. The field 
work was done during the months of July and August, and the collec­
tions were worked over at the laboratory at Beaufort. My thanks 
are due to Mr. Henry D. Aller, director of the Fisheries Laboratory at 
Beaufort, for placing every poasible convenience at my disposal, and 
to Mr. George A. Nicoll and Mr. William Dunn, of Newbern, North 
Carolina, for the use of their hunting camp, boats, and equipment 
while doing the field work. I am also indebted to Profs. D. S. John­
son and B. E. Livingston, of the Johns Hopkins University, for 
valuable suggestions and criticisms. 
The four lakes form a compact group situated in the eastern coastal 
plain of North Carolina, about 10 miles north of Bogue Sound. The 
region around the lakes is very flat and has a gray, loamy soil. Owing 
, +" I,he flatness of the country the rain water does not run off 
rapidly but stands on the soil and makes a large part of it swampy. 
The only cultivated land near any of the lakes is a small patch near 
but not bordering on Lake Ellis. The rest of it is covered with either 
forest or low pocosin. The latter is a region kept almost clear of 
trees by forest fires and covered with an almost impassable growth 
of small bushes and briars. 
The water supply of the lakes is obtained from the rain, either 
directly or through the neighboring swampy country. The depth of 
the water in the lakes depends on the amount of rainfall; but as the 
soil of the surrounding flat country is porous and covered with 0. 
dense growth, the water is held back, and there is a more or less 
constant supply. 
The natural outlets can not be seen from the lakes themselves, but 
are swamps leading to 0. stream. Canals have been dug from Lake 
Ellis and Long Lake. All the lakes drain to the Neuse River, but 
323 
324 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Great Lake also drains to Oak River. All four are close together, but 
the only two which are connected are Great and Ellis lakes. These 
are connected by a swamp through which water flows from Great 
Lake to Lake Ellis. The water in all the lakes is colored dark by 
organic matter. Great and Little lakes are about 8 feet deep, while 
Lake Ellis is generally less than 2 feet deep. The aquatic vegetation 
is scanty in all except Lake Ellis. 
LAKE ELLIS. 
PHYSICAL CHARACTERS. 
Lake Ellis has the general shape of an ellipse and is about 3 miles 
long by nearly 21 wide. 
The shore of the lake is covered with trees. The outer part of the 
water is overgrown with grasses and sedges, while the central part 
is largely filled with submerged vegetation. 
At the time that the lake was examined the average depth of tho 
greater part of it was about 22 inches, and it rarely exceeded 2 feet. 
Soon after this there were heavy rains for a week. When the lake was 
visited two days after the rains the water was 4 feet 6 inches deep. 
Tho next day it had fallen to 3 feet 4 inches. During the next week 
it fell only 2 inches more, but after this it fell somewhat more rapidly. 
Toward the edges of the lake tho water gradually becomes shallower, 
and the bottom grades into tho shore. 
The only inlet to Lako Ellis is through a swamp which reaches 
from Great Lake to its western end. It receives, however, a large 
quantity of water from the surrounding country, which is very flat 
and in many places swampy. The quantity of water received from 
Great Lake and from the surrounding country is regulated largely by 
the amount of rainfall. I am told on reliable authority that there are 
times when no water runs from Lake Ellis, but these times must be 
very rare. 
The lake is drained by two canals at the eastern end. The water 
flows into these through the part of the lake covered with grass. 
There i" a considerable current in the canals, but very little in the open 
part of the lake. The canals empty into Bear Branch, this being 
tributary to Slocums Creek which, in turn, empties into Neuse River. 
The water of the lake has a dark color from organic matter con­
tributed by the plants of the surrounding swamps and of the lake 
itself. 
For a long time there was a canal through the swamp between Lake 
Ellis and Great Lake, the same running through Lake Ellis and 
continuous with one of two issuing from the eastern end. The two 
latter completely drained the lake, and the water in them was 
utilized to turn a mill. About forty years ago the lake was planted 
• 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 325 
in rice, but this is said not to have done well. Since that time the 
canals have fIlled up considerably, and the lake has been for some 
years about the same size as at present. From what has been said 
it will be seen that the growth in the lake is of recent origin. 
In summer the temperature of the water rises from about 80° in 
the morning to anywhere between 90° and 105° about midday. The 
difference in temperature seems to be largely determined by the degree 
to which the sun is obscured by clouds. 
The soil of the bottom was originally a coarse sand, but the inflow 
from Great Lake and the interior current have carried humus and 
small soil particles to certain places and have thus changed its char­
acter. The difference in the character of the soil seems to be the 
chief factor in determining the local character of the flora, as the 
different zones (to be described later) occur in the same depth of 
water and have the same amount of light and heat. 
ZONES OF VEGETATION.a 
The zones depending on the depth of the water, described by Magnin 
(1893) for the lakes of the Jura and by Pieters (1894) for Lake 
St. Clair, are not present in this lake, as the water is not as deep as 
the deeper parts of the phragmitetum or outer part of the littoral 
zone of Magnin. In Lake Ellis there are, however, three distinct 
growths, all in the same depth of water, but occuring on different 
kinds of soil. For convenience these will be called the central, 
intermediate, and marginal zones. The plants of the marginal zone 
are emergent forms, chiefly grasses and sedges, while most of the 
plants of the other two are submerged. Figure 56 represents in a 
diagrammatic way the distribution of these zones. 
The vegetation of the central zone is chiefly composed of Erioca'lilon 
compressum either by itself or with Myriophyllum or with Eleocharis 
robbinsii. 
The intermediate zone is characterized by Philotria minor, 
Sphagnum, Eleocharis interstincta, E. mutata, Panicum homitomon, 
Nympluua advena, Castalia odorata, and Hydrocotyle. 
The plants of the marginal zone, as has been said. are largely 
grasses and sedges. The chief species is Baccialepis striata. 
To understand the disposition of these zones it is necessary to 
examine the physical factors which have changed the character of 
the surface soil in some places from a coarse sand to a fine mud. 
The water coming through the swamp from Great Lake brings debris, 
aThe Buggestions of the Commission of Phytogeographical Nomenclature of the 
Brussella Congress were not published at the time this paper was prepared. As DO 
misunderstanding can result from the author's use of the term' I zone," it is not thought 
advisable in his absence to disturb the form of the paper by substituting "girdle" aa 
proposed by the commission .. -EmTOR. 
326 CONTRIBUTIONS FROM THE NATIONAL HERRARIUM. 
, 
CENTRAL 
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MARGINAL 
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FlO. OO.-Dlagram of Lake EllIS . 
• 
, 
• 
• • 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 327 
consisting of soil particles and vegetable matter, mainly the latter, 
some of which is deposited at the western end and has enriched that 
part of the lake. Most of the d~bris, however, comes from the lake 
itself and a large part of this is carried by the current to the eastern 
end. Some debris is washed in from the shore at the sides, or blown 
by the wind from the interior of the lake to the sides, but the char­
acter here has not been changed to nearly the same extent that it has 
at the ends. Where the debris has been deposited the surface soil has 
been changed to a soft mud. This change is more pronounced at the 
ends, especially the eastern. From the ends toward the center the 
change becomes gradually less pronounced, until in the second fifth 
of the distance from the western to the easlern the soil is left a coarse 
sand, which is packed by the waves. The canal across the lake has 
been filled up with humus. 
The central zone is confined to the sandiest soil in the lake. The 
soil becomes muddier toward the outer part of this zone until it 
passes over into the intermediate zone. The soil here, in turn, gets 
muddier toward the outside until the inlermediategives way to the 
marginal zone. The marginal and intermediate zones extend around 
the central, but are widest at the ends and especially the eastern end. 
MARGINAL ZONE. 
The marginal zone is from 1,800 to 2,200 feet wide at the eastern 
end and about 1,300 feet wide at the western end. At the latter it 
extends into the lake along the line of the old canal as a narrow 
tongue for 1,450 feet, and at the former it extends farther along the 
canals than elsewhere. From the eastern end this zone decreases 
in width toward the sides until, in the second fifth of the distance 
from the western to the eastern end, it is about 500 feet wide on the 
southern side and disappears altogether for a short space on the north­
ern side. Except at the narrowest parts, that is, in the second fifth 
of the distance from the western to the eastern end, this zone extends 
far out into the deepest water of the lake while it does not extend into 
the sand of the second fifth even when this is in shallow water. 
Between and on ti,e sides of the canals at the eastern end where the 
soil is removed from the current there are rather sandy patches where 
the vegetation resembles that of the next zor.e. The principal growth 
on these patches is Eleocharis mutata and Castalia odorata. 
The roots of the grasses and sedges of the marginal zone are 
mostly in the surface mud and large clumps can be readily pulled up. 
But it is not to be supposed that mud is necessary for the growth of 
all of these plants, as a large number of tI,em are found on the land 
around the lakes. Here, however, ti,e soil is a gray loam and much 
softer and better than the coarse packed sand of the lnke. 
328 CONTRIBUTIONS FROM THE NATIONAl. HERBARIUM. 
INTERMEDIATE ZONE. 
The intermediate zone borders on the inner side of the one just 
described and has the same general shape. At the eastern end of the 
lake this is 1,650 feet wide and is characterized by a dense growth of 
Philotria mi1lO1". Besides this, Nymphaea advena, P01IUderia cordata, 
Hydrocotyle, and Sagittaria are found in great numbers, anel patches 
of Panicum Mmitcmum and Eleocharis interstincta are scattered here 
and there. Toward the sides of the lake this zone becomes narrower 
and the soil is in general less muddy, resembling in this respect the 
inner part of the zone at the eastern end. About halfway up the lake 
the intermediate zone has DIlrroweel in places to II widtJl of only II 
few feet. Panicum hemitomcm and Eleocharis interstincta are more 
prominent, while the growth of Philotria mi1lO1" is much thinner. 
Most of tJle other plants disappear to a great extent. In the second 
fifth of the distance from the western to the eastern end of the lake 
the intermediate zone becomes irregular. It runs along the marginal 
zone and also appears as patches of Panicum hemitomon and Eleocharis 
interstincta intermingled with the Eriocaulon compressum and Hko­
charis robbinsii of the wings of the central zone. A few scattered 
plants of Sagittaria are also found here. 
At the western end of the lake the intermediate zone is much nar­
rower than at the eastern end and the soil is in general less muddy. 
Here Sphagnum takes the place of the Philotria minor of the eastern 
end as the predominant plant in the vegetation. This zone extends 
around the tongue of grass of the marginal zone described above 
as following the canal. Here Gastalia odorata is found in great num­
bers, and it extends out into the canal for some distance after the 
grass has disappeared. The other most prominent plant of this part 
of the intermediate zone is Ekocharis interstincla. Where this has 
fenced in small bodies of water, so that the debris from decaying plant" 
has not been washed away, patches of Gastalia odorata are found. As 
has been said, the soil is much less muddy at the western than at the 
eastern end, and this probably accounts for the different character of 
the vegetation found in the intermediate zone at the two ends. 
The vegetation is in general more vigorous toward the outer or 
Muddier edge of this zone than nearer the central zone. The water 
lilies in the canal grow in very muddy soil and extend far out into the 
Inke. From these facts it seems probable that the soil toward the 
outer part of this zone does not become unfavorable, but that the 
plants of the intermediate zone are driven out by those of the 
marginal. 
Since the soil of that part of the eastern end of the intermediate 
zone which is nearest the marginal zone is muddier than the soil of 
the intermediate zone at the sides and western end of the lake, it 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 329 
would seem that the plants of the marginal zone do not occupy the 
soil at the eastern end as fast as the soil would support them. There 
seem to be two reasons for tbis, the presence of competitors to be 
driven out and the method of invasion by the plants of the marginal 
zone. Single plants of the gra9."OS and sedges of the marginal zone 
are rarely found in the intermediate zooe, but the plants of the 
marginal zone seem to advance as a solid stand by meaos of their 
rootstocks. 
• CENTRAL ZO>cE . 
The central zone is found on the sandiest soil. This is in the cen­
tml part of the lake aod occupies the greater part of it. Two wings 
also extend fur toward the shore in the second fifth of the distance 
from the western to the eastern end. In this second fifth the soil is 
vcry sandy, and in the center, where the water is about 22 inches 
deep, there is almost nothing but a sparse growth of Eriocauwn 
compressum. Toward the sides where the water becomes shallower, 
15 inches or less, there is a growth of Eleochari. robbinsii. This 
mrely extends into water over 15 inches deep and does not grow on 
soil which would support the plants of either the intermediate or mar­
ginal zones. This growth is included in the central zone because of 
its occnrrence with Eriocaulon compre.sum on sandy soil as well as on 
account of the small size of the plant aod its open growth. Eleo­
cha";'. robbinsii extends in for 700 feet on the south side and 1,525 feet 
011 the north side. 
Proceeding ill either direction from ahout the middle of the second 
fIfth of the distance from the western to the eastern end, the growth 
of Eriocaulon compressum becomes more abundant and is soon 
associated with " thick growth of Myriophyllum. This extends to 
the intermediate zone. In that part of the canal which runs across 
the lake and is not filled with grass or any of the plants of the 
intermediate zone the Myriophyllum grows more luxuriantly than 
elsewhere, showing that the increase in debris is not detrimental to 
its success and indicating that when this gives way to the plants of 
the intermediate zone it is because it can not compete with the more 
vigorous vegetation found there. 
COMPARISO:N OF ZONES. 
The different zones are characterized by different plants, but at 
the edges of the zones there is often the usual intermingling. 
. The mass of the vegetation characteristic of the different zones is 
in proportion to the muddiness of the soil. Eleocharis robbinsii and 
Erioca'l1lc-n compressum of the central zone are both small plants Rnd 
do not form dense patches, while Myriophyllum grows in n loose, 
fluffy mass with little bulk. The plants of the intermediate zone are 
• 
330 CONTRIBUTIONS FROM 'tHE NATIONAL HERBARIUM. 
much more robust than those of the central zone and form much denser 
masses, while the grasses and sedges of the marginal zone form a 
dense mass which extends high up above the water. The difference 
in the density of the stand of Panicum hemuomon and El80charis 
inters/incla of the intermediate zone and the grasses and sedges of the 
marginal zone is very noticeable, the latter forming a much denser 
stand. It seems that the larger growth takes possession of the soil 
occupied by a smaller one after the soil has become capable of sup-
porting the larger. . 
That the soil is the factor which determines the distribution is evi­
dent after a comparison of the zones. The depth of water, however, 
influences the distribution of some species in a zone. Eleocharis 
robbinsii of the central zone is rarely found in water over 15 inches 
deep; but if depth were the only factor we should expect to find the 
plants of the marginal zone where we find Eriocaulon compresmm and 
Eleocharis robbinsii. Some of the sedges of the marginal zone are also 
affected by the depth, but the plants of the marginal zone are just as 
vigorous in the deepest water of the lake as elsewhere. It is evident, 
then, that the depth of the water does not determine the disposition 
of the zones, for where the soil is muddy the marginal zone is in the 
deepest water, while, where the soil is sandy, the central zone extends 
into the shallow water. 
That light and heat are not important factors in this disposition is 
shown by the fact that the plants of all the zones are exposed to the 
direct sunlight, while the current is diffused and not strong enough to 
affect the heat to any appreciable extent. 
That distance from the shore and protection from wind do not play 
any important part is shown by the projection of the tongue of the 
marginal zone out into the lake along the canal at the western end, 
and by the extension of the water lilies along the canal even farther, 
in separate patches- indeed nearly to the middle of the lake. The 
marginal zone is 2,200 feet wide at the eastern end, while at the 
sides it may disappear altogether. Another proof of this is afforded 
by the patches between the canals at the eastern end, where the soil 
is removed from the current and is sl1miy. Hel'e a growth resem­
bling that of the intermediate zone is completely surrounded hy the 
marginal. 
Summarizing, briefly, some of the more striking instances whieh 
seem to show that the chamcter of the soi! determines the zonation 
are: Between the canals at the eastern end where sandy patches are 
surrounded by muddy soil the intermediate zone is surrounded by 
the marginal. At the eastern end where the soil is muddy the mar­
ginal zone is 2,200 feet wide and extends far out into the deepest 
water of the lake, while at the sides where the soil is sandy it may 
disappear entirely and the central zone occur in the shallow water • 
• 
IlIlOWN-PLANT LIFE OF NORTH CAROLINA LAKES. flat 
Where the canal has become filled with debris, the marginal and inter­
mediate zones extend as a narrow tongue far out into the lake. 
The migration of the plants from one zone into the ground occu­
pied by the next seems to be going on rapidly, but, owing partly to 
a conflict with the plants present, the invaders probably do not 
occupy at once all the ground which is capable of supporting them. 
The plants themselves are important factors in determining the 
deposition of debris and the consequent local change in the character 
of the soil. The plants of the marginal zone decay largely where 
they fall. The thick stand keeps debris from being washed into this 
zone and causes it to be deposited on the intermediate zone. The 
plants of the intermediate zone also catch a good deal of debris. 
Thus, as the marginal zone advances, new soil is prepared in the . 
intermediate. The plants of the central zone by their decay and by 
catching debris also cause some change in that part of the lake, and 
especially near the intermediate zone; but the plants of the central 
zone, being submerged, must depend largely on that part of the debris 
which settles to the bottom. 
It would seem probable that the marginal zone will finally extend 
over the whole lake. It also seems probable that by the decay of the 
plants in this zone the level of the ground will in time be raised 
sufficiently to support a growth of Pinus serotina and Liquidambar 
styraciftua. It is likely, however, that the grasses and sedges will 
occupy the whole of the bke a long time before the trees make any 
very great headway. 
ISI.ANDS AND TREES. 
In the water near the marginal or grass zone are a number of small 
places where the soil comes nearly or quite to the surface of the 
water. On these spots small trees of Acer rumm are found, and 
around these is generally a growth of Panicum hemuom<Yn, or some­
times Sacciolepis striata. A few small specimens of Acer rubrum are 
also found in the marginal zone. Where the canal banks near the 
edge of the lake are somewhat higher than the surrounding ground, 
there is found Acer rubrum, Liquidambar 8tyraciftua, and Pinus 
8erotina. A few small specimens of Taxodium diBtichum also occur 
in the lake. None of these trees are large enough or numerous 
enough to shade the lake to any appreciable extent except for a short 
distance along the northern canal at the eastern end. The trees in 
the lake do not seem to be under favorable conditions. 
BANKS OF TH e: LA R E. 
Small plants of Pinus serotina and LUzuidambar styraciftua are 
invading the marginal zone where this grades into the shore. The 
shores of the lake are generally marshy and covered with Pinus 
332 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
serotina and Liquidambar styracijlua. Sphagnum often covers the 
ground. The undergrowth Vllries in different places. The most 
prominent constituents are small plants of Pinus serotina and Liquid­
ambar styraciftua, nex glabra, Drosera longifolia, Limod<Jrum tuber­
osum, Rheria mariana, Blephariglottis cristata, Magnolia mrginiana, 
Lycopodium alopecuroides, Lycopodium adpre88um, Persea pubescens, 
Arundinaria tecta, Viola sp., Xyris, and some of the sedges of the 
lake. The trees are often festooned with Dendropogon usneoides or 
covered with lichens. 
ALGAL FLORA. 
The algal flora of Lake Ellis is rich in number both of species and of 
individuals. The great mass of plants growing in the lake gives a 
large suriace for attached forms. All of the submerged plants and 
the stems and the under suri"ce of the floating leaves are covered 
with these. The filamentous forms growing on these suriaces and 
the submerged plants themselves form habitats for diatoms and 
desmids, which occur in great numbers. 
The green algre are present in great abundance, but do not at this 
season form dense masse.' and do not seem to be in a vigorous c.ondi­
tion. The blue green algre arc even more abundant than the green 
algae and seem to be in better condition. This seems to agree with 
the conclusions of Fritsch (1907) that the blue greens are bettcr able 
to endure a high temperature than the green algre. 
The conditions for algal growth are fairly uniform over the whole 
lake, and the distribution of the species is fairly general. 
Besides the algre, there are large numbers of bacteria, especially 
at the suriaee. 
The following is a list of the principnl al!(", found in Lake Ellis: 
AMbarn. jlosaquae (Bg.) Kg. 
Ratrachosperm1l1n fIIonibiJormt Roth. 
Bulbockadc flp. 
Chantramia sp. 
Hapalosiphon ltrebi.s8onii 1lg. 
Lyngbia Ap. 
Merismopedia glauca Bg. 
Oedogonium ap. 
Spirogyra insignis (1Ia.'1~ . ) Kg. 
8pirogyra sp. 
Ulothrix 8p. 
Zygnema purpureum Wolle. 
Zygnema ap. 
GREAT LAKE. 
PHlI SICAL OHA RACTERS. 
Grcnt Lnke lies to the west of Lake EllIS. It is kidney-shaped, and 
about H miles long by 3i wide in the widest pl\rt, with an area of 
about 3.000 acres. In the center of the lake the water is about 8 feet 
'deep~ , 
,The lake has no inlet, but tho wnter comes from the surrounding 
country, which is partly swampy. Owing to the flatness of this 
, 
country/the porousncss of the soil, nnd the dense growth with which 
• 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 333 
it is covered, the rain water does not run off rapidly, but furnishes a 
more or less constaut water supply to the lake. There are two out­
lets, both through swamps. One is at the eastern end and goes to 
Lake Ellis, while the other is at tile northern side and goes to Hunters 
Creek, which flows into Oak River. 
The water is coffee-colored from dissolved and suspended organic 
matter. 
The temperature of the water rises from about 800 F. in the morn­
ing to anywhere between 900 and 1020 at midday. 1'he difference 
seems to be largely regulated by the brightness of the sun. 
The soil, from the shore to a point where the water has a depth of 
abou t 5 feet, is composed of a coarse sand, while in the center of the 
lake it is a soft mud. This difference seems to be due to the fact that 
humus and fine soil particles are carried about by the waves until 
they settle in the deepest part and make that muddy, while the 
original coarse, sandy soil is left at the edges. There are small 
patches of peaty soil near the shore in the sandy part of the bottom. 
These are probably at places where Taxodium distichum has grown 
and then decayed, as these trees grow in this part of the lake and 
occupy spots of about the same size. The sand is packed hard by 
the waves and when struck resounds like rock. During storms, 
however, it is shifted about considerably, as is shown by the fact 
that a boat which was left anchored in a sheltered bay during four 
days of stormy weather was, at the end of that time, half full of sand. 
The shore line has slight irregularities forming numerous miniature 
bays. The water is generally about 6 to 12 inches deep at the shore, 
but the slope of the bottom is quite gradual. The depth of the water 
at the shore seems to be caused largely by the waves washing up 
against the shore vegetation. 
AQUATIC VEGETATION. 
The aquatic vegetation of Great Lake is very scanty. As in Lake 
Ellis all of the plllnts would be included in the phraglilitetum or 
outer part of the littoral zone of Magnin (1893). All of the species 
in Greut Lake are found in the intermediate zone of Lake Ellis. 
Taxodium distichum is founel in the lake near the shore at the east­
ern end of Grellt Lake. The reusons for its absence at the western 
end will be apparent when the vegetation of the shore is discussed. 
Where the waves wash the bases of these and where stumps or knees 
come to the surface they are often covered with moss which is partly 
submerged. The only other vegetation, except algID, found in the 
lake consisted of some patches of Nyml'haea advena, a few patches of 
Panicum hemilo"""" and one of X yris caroliniana. These seem to 
get a start in the peaty places and probably lead a precarious existence 
owing to the shifting sand, which is likely to bury them or cILuse their 
• 
• 
• 
334 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
roots to be exposed. The scarcity of aquatic vegetation is probably 
due to the packed and shifting sand where the water is shallow and, 
where it is deeper and the bottom muddy, to the dark color of the 
water which excludes the sunlight. 
FLORA OF 'rHE BANKS. 
The vegetation on the edges of the lake presents quite a different 
aspect at the western and eastern ends. At the western end there is 
a low pocosin over which forest fires sweep at frequent intervals. 
The eastern half is protected by swamps from the fires and the 
ground is covered with a growth of large trees, consisting largely of 
Tazodium distichum, Nyssa biflora, Quercus nigra, !lex opaw, and 
Liquidambar styral:ijlua. The undergrowth is quite dense and is char­
acterized by MoreUa cerifera, Leucothoe racemosa, Eupatorium maC'Ula­
tum, OyriUa racemifiora, Pieri. nitida, n ex cassine, Arundinaria tecta, 
Magnolia virginiana, Olethra alnifolia, and Comus alternifolia. Wher­
ever soil has been caught on tho stumps or knees of the Taxodium dis­
tichum growing in the lake this soil supports a growth of some kind, 
generally Eupatorium maculatum or Olethra alnifolia. The trees are 
usually festooned with Dendropogon usneoides or sometimes Usnea. 
Polypodium polypodioides, lichens, mosses, and liverworts all grow 
on the trees in great abundance. Climbing over the trees and shrubs 
are a large number of vines. The chief species arc Vitis rotundifolia, 
Smilax laurifolia, and Apio. apio •. . Altogether this part of the shore 
supports quite a luxuriant vegetation, while all of the w~stern half 
is covered with low pocosin, which consists of bushes a few feet high 
and briars. 
Scattered through tlus growth are small pine trees, but the charred 
remains of those wluch have been killed by fire are about as numer­
ous as the live ones. The physical conditions, except the humus con­
tent of the soil, seem to be the same here as at the eastern end, and it 
is probable that this part of the shore would be covered with trees 
but for the forest fires, which kill them and burn the humus out of the 
soil. These forest fires are frequent in this part of the country. 
The chief plants found in tho low pocosin at the western end nre 
Persea pubescens, Pieris nitida, lIyperiC'Um sp., and Smilax laurifolia. 
ALGAL FLORA. 
The algal flora of Great Lake is very scanty. Bacteria are present, 
however, in great abundance, especially floating at the surface, on 
the su bmerged parts of the mosses, and on the trees near the surface 
of the water . 
The most abundant alga is Oedogonium which coats the stems 
and under su rface of the leaves of Nymplw.ea advena. Algre are also 
found to some extent on the stems of Sacciclepis 8triata and the 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 335 
• 
submerged parts of the mosses and trees. The scanty growth on 
the mosses and trees is associated with the great abundance of 
bacteria. Aside from the Oedogonium on the leaves of Nymplw,ea 
adveoo the green algre are much less abundant than the blue green 
algre. The latter seem to be better able to stand the adverse 
conditions. 
Tbe growth of diatoms and desmids as well as other algre is scanty. 
They are found to some extent in the mosses and in the mud at the 
bottom of the lake, but are very scarce at the surface. This scarcity 
is associated with the lack of supporting plants, the darkness of the 
water over the mud, and the presence of bacteria at the surface. 
The following is a list of the principal algre founel in Great Lake: 
AnablUnaflosaquae (Bg.) Kg. 
Bulbcdwel< sp. 
ChantraMia sp. 
Hapaionphon brebi3wnii Bg. 
Lyngbia ,po 
Ocdogonium sp. 
Scenede81TlWl caudalw Corda. 
Sircniphon 8p. 
Spirogyra 8p. 
Ulothrix sp. 
LITTLE LAKE. 
Little Lake lies to the north of Lake Ellis and is the smallest of 
the group. It is nearly round, with a diameter of a little over a 
mile and a half and an aren of about 400 acres. The outlet is through 
a swamp which extends to Bear Branch, this flowing into Slocums 
Creek and this, in turn, into Neuse River. 
The physical features of Little Lake are like those described as 
belonging to Great Lake. It has the same kind of bottom and 
shore and the same character and depth of water. In the center 
the bottom is muddy, while nearer the shore it is sandy. The water 
is dark-colored and in the center is about 8 feet deep. 
The only vegetation found in the Inke consisted of n small clump 
of X yris carolinia.oo growing on an old log. The vegetation on 
the shore resembles very closely that of the shore of Great Lake 
except that there is here less low pocosin, and Ghamaecyparis thyoides 
takes the place of Taxodium distichum, which is not found on the 
shore of Little Lake or in the luke itself. 
LONG LAKE. 
Long Lake lies to the northwest of Little Lake. It is R little 
over 3 miles long and nearly 2 wide in the widest part, with an area 
of about 1,286 acres. 
This lake was visited but not thoroughly examined. The physical 
conditions and flora seemed to resemble very closely those of Little 
Lake. 
• • • 
• 
336 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
TB .:ORETICAL DISCUSSION. 
ZONATION. 
The relation of soils to aquatic vegetation has been very little 
studied. It is genemlly believed that the vl\luo of a soil depends 
largely on its ability to retain moisture. This, however, can hardly 
be true for submerged soil which is alwnys saturated with wnter. 
Pieters (1901), in his work on Lake Erie, hlls shown that there is 
probably a relation between the soil and aquatic vegetation. He 
says that his soil samples were not numerous euough to mllke gen­
eml deductions possible, but ho indicates the direction in which they 
seem to point. To quote: "As a rule the soils on which plants 
occurred in abundance were composed largely of firm sand and con­
tained relatively little silt, fine silt, fmd clay, while the soils on which 
few or no plants occurred, although the depth of wntor and other 
physical conditions were favornble, were composed largely of silt, 
fine silt, and clay, and were poor in fme sand and very fine sand." 
And again: "The water in sandy soils is undoubtedly better aerated 
than that in clay soils, though both are under water, because in the 
former case the water passes through the soil more rapidly than it 
• does in the latter, and it would seem that even the roots of aquatics 
are unable to thrive in a soil so poor in oxygen as the saturated heavy 
clays." This explanation can not account for the zonation in L"ke 
Ellis, Cor here we have no clay and the poorest soil is II coarse sand. 
Pond (1903) as the result of experiments concluded that Philo tria, 
Myriophyllum, and a number oC other plants grew better when 
rooted in a good soil than when anchored over a soil or rooted in 
clean washed sand. The writer repeated these experiments with 
Ph-i1<Jtria ca1UZden8is in the greenhouse oC the Johns Hopkins U ni­
versity during the winter and spring of 1910. In these experiments, 
which will be described more fully in a later paper, as in those per­
formed by Pond, the plants rooted in a good soil grew better than 
those anchored over the .ame soil. In the latter case, however, the 
soil soon became covered by 0. dense growl.h oC a1gre. When the 
same alg", were transCerred to 0. jar with rooted plants the alg", 
failed to make any appreciable growth. This suggested that the 
slight growth of the anchored plants of Philo tria was due to the use 
by the algre of some substanee whieh came from the soil and which, 
in the case of the rooted plants, could be used by them, since they 
were nearer the soil than the anchored ones. Further experiments 
seemed to show that this substance was CO" derived Crom tho organic 
matter in the soil. Plants were grown under a number of different 
conditions but in no case did they make a normal growth unless 
some CO, other than that obtained by the water Crom tbe air was 
supplied them. When a soil which contained little or no organic 
• 
BROWN PLANT LIFE OF NORTH CAROLINA LAKED. 337 
matter, even though it were rich in mineral substances, was used 
the plants made no better growth when rooted than when floating 
free in the water. This was true both when CO, was and was not 
supplied artificially. These experiments seem to show that the CO, 
derived from the organic matter of the soil may be an important ele­
ment in the growth of submerged plants and may be a factor in the 
distribution of the submerged plants of Lake Ellis. This is, however, 
probably not the only factor concerned, as this conclusion can hardly 
apply to the emergent forms and it is probable that the soil factors 
which determine the distribution of the emergent forms also affect 
the submerged ones. 
Why the nature of the soil should determine the distribution of the 
emergent plants in Lake Ellis is not clear. When we remember that 
soils have the property 'of withdrawing salts from solution and that 
plants can concentrate salts from very dilute solutions it does not 
seem probable that anywhere in Lake Ellis there are not enough salts 
to support the plants of the marginal zone. 
The physical nature of the soil, on the other hand, may be a very 
important factor in determining the zonation. Most of the plants 
of the two outer zones grow rapidly and have large and rapidly grow­
ing roots. The hard-packed condition of the sand would probably 
offer considerable resistance to the large rhizomes and roots, while 
the sharp edges of the coarse grains might possibly injure them as 
they were being pushed through the packed soil. The mud, however, 
would offer little resistance or injury to the large, soft, and rapidly 
growing roots and rhizomes. 
PRODUCTION OF PHYTOPLANKTON. 
Kofoid (1903) after making careful quantitative detenninations of 
the plankton in a number of lakes concluded that "The amount of 
plankton produced by bodies of fresh water is, other things being 
equal, in some inverse ratio pl'<!portional to the amount of its gross 
aquntic vegetation of the submerged sort." He attributes the scar­
city of plankton in lakes containing submerged vegetation to a num­
ber of causes, but chiefly to the removal from the water, hy the larger 
aquatics, of a great part of the available food material. 
Pond (1903), as mentioned above, found that a numher of aquatics 
grew better when rooted in a good soil than when anchored over the 
same soil. From these and other experiments he concluded that 
these plants" are dependent upon their rooting in the soil for opti­
mum growth," and that" the roots of these plants are organs of 
absorption as well as of attachment." He says further that these 
conclusions are probably applicable to all aquatic plants which grow 
rooted in a soil substratum. 
70272°-VOL 13, I'T 10-11 3 
• 
33B CONTRIBUTIONS FROM THE NATiONAL RERBARIl:M. 
In a discussion of Pond's experiments by Reighard and Pond 
(Pond, 1903), these authors conclude that, if Pond's observations are 
correct, submerged aquatics when rooted not only ad as a mechan­
ical support for .. !gill, but .. Iso play an important nutritive rl>le by 
taking mineral food from the soil and organizing it into vegetable 
matter. "Upon the decay of the vegetable matter tlus food material 
is believed to pass into solution in the water. It should there nourish 
the plankton alg"'." Reighard and Pond ascribe Kofoid's results 
to the fact that the vegetation with wluch he was dealing was largely 
Ceratophyllum, and therefore not rooted. 
In the experiments mentioned above in wluch Philotria cana­
densis grew as well when floating free in the water as when rooted 
in the soil, root hairs were not developed by the floating plants. This 
suggests that Philo tria draws a large part of its nutriment through 
its leaves and may therefore competo with the plankton alglll for 
mineral salts, as well as for CO,. 
We have already see.n that plants of Philo tria grow bettor when 
BOrne CO" other than that obtained by the water from the air, is sup­
plied them. The same thing is truo of many algill. A large number 
of theso wore tried in different solutions, both with and \\~thout the 
artificial addition of CO,. In every case they made a much better 
growth when CO, was added to the solution, and in a number of cases 
in which they would not grow in a solution \\~thout the addition of CO, 
they made a vigorous growth when this was added. The need of an 
abundant supply of CO" which is shown by both Philotria and many 
algre, would suggest that there may be a sharp competition for CO, 
between these forms, and that the growth of such plants as Philotria 
would be detrimental to the production of phytoplankton. In a large 
number of cases in wluch various algre were grown in jars with and 
without Philotria, it was found that in every case, the algre grew much 
better when there was no Philotria present. Tlus was true in all of 
the solutions tried, both when the Philo tria was and was not rooted. 
It is evident, therefore, that the presence of such a plant as Philotria 
ie in some way harmful to phytoplankton, and since variations in the 
amount of CO, control the growth of the plankton alglll to a great 
extent it is not unlikely that the effect of Philotria on the algm is due 
in large part to the use of CO, by Philo tria. It is also probable that 
the amount of CO, present in a fresh-water lake will be a more imporlr 
ant factor than the amount of mineral matter in determining the 
quantity of phytoplankton produced. 
It haa been shown that Great Lake with little submerged vegeta­
tion has a very scanty phytoplankton, while Lake Ellis, with a great 
quantity of submerged vegetation, had an abundant phytoplankton. 
These results appear at :first to be contrary to the conclusions drawn 
from the experiments; but in Lake Ellis the shallow water, allo\\IDg 
the use of sunlight by the plants, is probably more favorable to both 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 339 
phanerogams and algro than is the deeper water of Great Lake. 
The phanerogams, by giving mechanical support to the algro, may 
also place these in a more advantageous position in relation to the 
sunlight and thus counterbalance to some extent the harmful effect 
due to their competition. 
SUMMARY. 
The whole of the bottom of Lake Ellis is covered with vegetation. 
There are three distinct zones or successions occurring in the same 
depth of water, but on different soils. The central zone, found on the 
sandiest soil, is characterized by Eriocaulon compressum, Eleocharis 
robbinsii, and Myriophyllum. The intermediate zone, on muddier 
soil, is characterized by Philotria minor, Sphagnum, Ekocharis inter­
stincta, Panicum hemitomon, Nyml'haea advena, and Castalia odorata· 
The marginal zone, found on the muddiest soil, is composed mostly of 
grasses and sedges, the chief component being Sacciolepis striata. 
The disposition of the three zones seems to be determined by the 
character of the soil. The plants of the intermediate zone invade 
the territory of the central as it becomes muddier by the depositing 
of debris, while the plants of the marginal zone in turn invade the 
territory of the intermediate. As this invasion continues the grasses 
and sedges will occupy more and more of the lake and probably will 
finally drive out the plants of the other zones. The vegetation in the 
lake is of recent origin and the invasion seems to be going on rapidly. 
A few small plants of Pinus serotina, Acer rubrum, and Liquidambar 
styraciflua are found when the soil comes near the surface of the water. 
Pinus Berotina and Liquidambar styraciflua are invading the growth 
of grasses and sedges from the outer edge. 
The emergent vegetation growing in Great Lake consists of TaXI>­
dium distichum, Nyml'haea advena, Panicum hemitomon, and X yris 
caroliniana. The aquatic vegetation is very scanty. In the shallow 
water this is probably due to the hard, shifting sand which forms 
the bottom, while in the deeper parts of the lake where the bottom 
is muddy, the dark color of the water probably excludes too much 
sunlight to allow the growth of plants. 
The shore of the eastern half of the lake is covered with large 
trees under which there is a dense undergrowth. The shore of the 
western half is covered with low bushes and briers and a few small 
pine trees. The scarcity of trees here seems to be due to forest 
fires, which sweep over this part of the shore, whereas the other half 
is protected by swamps. . 
The algal flora of Lake Ellis is rich in both species and individuals. 
The green algro are abundant but not in good condition in the 
summer season, while the blue green algro are more abundant and 
more vigorous. The blue green seem to endure the high and change­
able temperature better then the green nlgro. 
• 
340 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
The algal flora of Great Lake is very scanty and this is associated 
with an absence of supporting plants, the darkness of the water, and 
the presence of great quantities of bacteria. 
The phanerogams in Lake Ellis compete with the algro for CO, and 
possibly also for mineral matter, and thus probably tend to decrease 
the amount of phytoplankton, although the mechanical support which 
they afford the algro may counterbalance the effect of the competition 
to some extent. 
THE JOHNS HOPKINS UNIVERSITY, 
Baltimore, Maryland. 
LITERATURE CITED. 
Fritsch, F. E. The aubaeria.l and freshwater algal flora of the Tropicf'!. Annals of 
Botany 21: 23:>--276. 1907. 
Xofoid, C. A. The Plankton of the Illinois River, 1894-1899, with introductory notes 
on the hydrography of the Illinois River and its basin. Part 1. Quantitative 
Investigations and General Results. Bulletin of the Illinois State Laboratory of 
NaturallIistory 6: 91>--629. 50 plates. 1903. 
Jilagnin, A. Recherches Bur 1& vegetation dee Lacs du Jura. Revue G~nemle de 
Botanique 6: 241, 303. 1893. 
Pieters, A. J. The plants of Lake St. Clair. Bulletin of the Michigan Fish Commis­
sion, No.2. 1894. 
--.. The plants of Western Lake Erie, with observations on their di!'ltribution. 
Bulletin of the U. S. Fish Commission 21: 57-79.1902. 
Pond, R. H. The biological relation of aquatic plants to the substratum. U. S. 
Commission of Fish and Fisheries, Report of the Commissioner 29: 483-526. 
1905. 
LIST OF PLANTS COLLECTED BY W. H. BROWN IN NORTH 
CAROLINA . 
Of the following list the Juncaceae were determined by Mr. Fred­
erick V. Coville, the Pteridophyta by Mr. William R. Maxon, and 
the remainder by Mr. Paul C. Standley. The numbers following the 
names are the collection numbers. 
Osmunda regalia L. 33. 
Anchistea virginica. (L.) Preal. 105. 
Lorinaeria areolata. (L.) Presl. 30. 
Polypodium polypodioides (L.) Hitcho. 
!l3. 
Lycopodium adpreesum (Chapm.) Lloyd 
& Underw. 14. 
Lycopodium alopecuroides L. 41. 
Cha.maecyparis thyoides (L.) B. S. P. 
!l5. 
Pinua eerotina Michx. 65, 103. 
Taxodium distichum (L.) Rich. 10. 
Typha Intifoli. L. !l2. 
Sagittsri. teres S. Wa". 31. 
Philotria minor (Engelm.) Small. 4. 
Arundinari. tecta (W.lt.) Muh!. 108. 
Panicum hemitomon Schult. 42. 
Panicum lucidum Ashe. 83. 
Panicum scabriusculum Ell. 52. 
Sacciolepis striata (L.) Nash. 43. 
Carex macrokolea Steud. 17. 
Cyperus haspsn L. 34. 
Dulichium arundinaceum (L.) Britton. 
46. 
Fuirena hiapida. Ell. 53. 
Eleocharia int.erstincta. (Vahl) Room. &; 
Schult. 18. 
Eleochari. mutata (L.) Roem. & Schult. 
74, 75. 
Eleocharis prolif.rIo Torr. 63. 
• 
BROWN-PLANT LIFE OF NORTH CAROLINA LAKES. 341 
Eleocharis quadrangulata (Michx.) Room. 
& Schult. 76. 
Eleocba.rie robbiosii Oakes. 26. 
Eleocharis tuberculosa (Micbx.) Roem. 
& Schult. 24. 
Eriophorum virginicum L. 67. 
Rynch"'pora axillaris (Lam.) Britwn. 
8,6l. 
Rynchoopor& distans Null. 40. 
Rynchoepora inexpaD88. (Mich:r. .) Vahl. 
11. 
Rynchoepora. macroetachya Torr. 13J 15, 
62. 
Rynchoepora torreyana A. Gray. 39. 
Scirpu8 americanua Vahl. 7. 
Scirpua eriophorum Michx. 48. 
Scirpus occidentalis (S. Wata.) Ch .... 41. 
Xyrie carolinjsn& Walt. 1. 
Xyris fimbriata Ell. 50. 
Eriocaulon compreeaum Lam. 66. 
Eriocaulon decangulare L. 49. 
Pontederiacorda.ta L. 70. 
Dendropogon usnooides (L.) Ral. 110. 
Juncuea.cuminatus Michx. 45. 
JUDCUB aristulatus Michx. 68, 69 . 
Junells canadensis 1. Gay. 38. 
Junella effwiUe L. 9. 
Smilax laurifolia L. 54. 
Blephariglottis cri.tata (Michx.) Ral. 16. 
Limodorum tuberoetim L. 27. 
Morella cerilera (L.) Small. 100. 
Salix longipes Shuttlew. 20. 
Quercus nigra L. 93. 
Phoradendron fiaveecens (Pursh) Nutt. 
114. 
Persic&ria hydropiperoides (Michx.) 
Small. 44. 
Magnolia virginiana L. 78. 
Nelumbo lutea (Willd.) Pers. 71, 73. 
Castalia odorata (Dryand.) Woodr. & 
Wood. 6. 
Nymphaea advena Ait. 72 . 
• 
Droeera intermedia Hayne. 22 . 
Sarracenia purpurea L. 23. 
Decumaria barbara L. 97. 
Itea. virginica L. 59. 
Liquidambar etyracifiua L. 21. 
Rosa. ca.rolina L. 109. 
Apiosapios(L.)M.cM . 89. 
Polygalacymooa Walt. 3. 
Cyrilla r&eemitlora L. 92. 
!lex glab", L. 55. 
!lex lucida (Ait.) Torr. & Gr. 82. 
Ilex opaca Ait. 90. 
Acer drummondii Hook. & Am. 101. 
Acer rubrum L. 12. 
Vitia rotundHolia Michx. 94, 95. 
Ascyrum bypericoidee L. 91. 
Hypericum DlACuiatum Wali.. 81. 
Hypericum eubpetiolatum Bickn.? 99. 
Gordonia laaiantha (L.) Ellie. 56. 
Pe ... a borbonia (L.) Spreng. 51 . 
Pe ... a pubcaccns (Pursh) Sorg. 2 
Rhexia mariana L. 19. 
Decodon verticillatus (L.) Ell. 64. 
Myriophyllum pinnatum (Walt.) B. S. 
P. 5. 
Ny .... bido", Walt. 67. 
Hydrocotyle umbellata L. 28, 35. 
Clethra alnilolia L. 77. 
Azalea viscOB& L. 87. 
Chamaedaphno calycuJata (L.) Moench . 
37l. 
Leucothoe elongata Small. 102. 
Pieris nitida (Bartr.) Benth. & Hook. 88. 
Symplocoe tinctoria (L.) L'Her. 86. 
UtricllJa.ria purpurea Walt. 25. 
Bignonia crucigera L. 79. 
Lonicera. japonica Thunb. 98. 
Viburnum nudum L. 36. 
Eupa.torium hyseopifolium L. 107. 
Eupa.torium maculatum L. 96. 
Pluchea loetida (L.) B. S. P. 58.