356 safford: myrmecophilous acacias
of Minerals : Fremontite = Natramblygonite withdraws the name
natramblygonite and substitutes for the mineral Na(A10H)P04
the name fre7nontite, after Fremont County, Colorado.
BOTANY.—Acacia cornigera and its allies. William Edwin
Safford, Bureau of Plant Industry.
In the course of a recent study of the myrmecophilous Acacias
in the U. S. National Herbarium the author encountered a nimiber
of undescribed species, some of which differ fundamentally from
any hitherto known. Much confusion was found also in the
existing classification of these plants, due largely to the fact that,
in describing species, the early authors had failed to designate
definite types. Thus, under Acacia cornigera (Mimosa cornigera
L.) several distinct species were cited by Willdenow as possible
synonyms, a fact which was recognized by Schlechtendal and
Chamisso in their study of certain specimens collected in Mexico
by Schiede. But these authors in turn included under their
Acacia sphaerocephala two, if not three species, one of which has
recently been described by Dr. Heinrich Schenck, of Darmstadt,
under the name Acacia veracruzensis. To make the confusion
still greater, Bentham in his Revision of the Mimoseae,^ "rede-
scribed" Acacia sphaerocephala and A. spadicigera but applied
these names to species quite distinct from those so-called by
Schlechtendal and Chamisso, while he dropped Acacia cornigera,
a species distinct from both A . sphaerocephala and A . spadicigera,
based upon a plant growing in the garden of George Clifford,
a specimen of which exists in the Linnaean Herbarium (no. 4).
The synonyms cited by Bentham are even more heterogeneous
than those of Linnaeus.
The absence of flowers and fruits from the specimens of myr-
mecophilous Acacias described by the early botanists has been the
chief cause of the mistakes of later authors. Fortunately the
material in the U. S. National Herbarium includes specimens of
fruits as well as of flowers of nearly all the species. The present
writer recognized the fact that these fruits, which are of several
distinct forms, ofl"er a means of separating the species into a
^ Trans. Linn. Soc. Lond. 30. 1875.
safford: myrmecophilous acacias 357
number of well defined natural groups. When it came to his
notice that Dr. Schenck was also engaged in studying the myrme-
cophilous Acacias, the writer postponed the publication of his
paper in deference to Dr. Schenck, from whom he received a
most courteous acknowledgment. ^
Dr. Schenck based his classification principally upon the
venation of the leaflets and upon the general form of the inflores-
cence. In his material fruits of several species were lacking.
On the receipt of photographs of further specimens of his newly
established species, many of which included seed pods, Dr. Schenck
realized the importance of using the latter as a basis for natural
classification.^ As it has become necessary to defer the publica-
tion of the wTiter's monograph of the myrmecophilous Acacias, it
is thought advisable to offer the present preliminary paper, in
which a classification of the group is presented together with
descriptions of nine new species.
KEY TO THE GROUPS
Involucre situated near the base or at least below
the middle of the peduncle; interfloral
pedicelled bracteoles peltate; spines
glabrous
Pericarp indehiscent, inflated, terminating in
an acute spine-like beak I. Ceratophysae.
Pericarp dehisc6nt
Fruit a pod, opening b}-- a dorsal and a
ventral suture
Flowers in globose heads; pods some-
times very long and slender .. . II. Globuliferae.
Flowers in cjdindrical spikes; pods
short and relatively broad III. Leguminiferae.
Fruit a follicle, opening by a single suture. IV. Folliculares.
Involucre situated at or above the middle of the
peduncle, the latter pubescent or hirtel-
lous; interfloral pedicelled bracteoles not
peltate spines puberulent when young ... V.; Hebacanthae.
-See H. Schenck, "Die myrmekophilen Acacia-Arten," Bot. Jahrb. Engler 50:
449-487. 1914.
' "Die BeschaffenheitderFriichtedlirftevielleicht zur endgiiltigen Unterscheid-
ung der Artengruppen der Ameisenakazien mindestens ebenso wichtige, vielleicht
noch bessere Anhaltspunkte geben wie die Form der Inflorescenzen." Bot.
Jahrb. Engler 50: 480. 1914.
358 safford: myrmecophilous acacias
GROUP I. CERATOPHYSAE^
Pericarp indehiscent, inflated, thin, fragile, terminating in a sharp
spine-like beak. Nectar glands of the petiole and often of the lower
rachis, elongated, crater-like, opening by a linear aperture with a
raised (marginal) rim.
Section 1. Spadicigerae Schenck
Flowers in spadix-Iike cylindrical spikes, densely crowded on a fusiform
receptacle; peduncles thickened, bearing a 4-parted calyx-like involucel
near the base; minute interfloral pedicelled bracteoles with peltate,
acuminate laminae, in form often resembling the leaf of an Arum.
Midrib and upcurved lateral nerves of the leaflets usually conspicuous
beneath.
1. Acacia spadicigera Schlecht. & Cham. Linnaea 5: 595. 1830; not
Acacia spadicigera Benth. Trans. Linn. Soc. London 30^: 514. 1875.
Type in the Halle Herbarium, collected near La Laguna Verde, State
of Veracruz, Mexico, in March, 1820, by Schiede (no. 685). Photo-
graph and fragments of type in the U. S. National Herbarium.
2. Acacia cubensis Schenck, Repert. Nov. Sp. Fedde 12: 360. 1913.-
Bot. Jahrb. Engler 50: 460. 1914.
Type in the West Indian Herbarium of Krug and Urban, Berlin,
collected in northern Cuba, April 21, 1863, by C. Wright (no. 2402);
specimens collected by C. Wright, bearing the same number, in the
Grisebach Herbarium, Gottingen, and in the Gray Herbarium.
3. Acacia Hemandezii sp. nov.^ Closely related to Acacia spadici-
gera Schlecht. & Cham, and A. nicoijensis Schenck, but readily distin-
guished from the former by the subsessile flower spikes, scabrous before
anthesis owing to the recurved points of the bracteoles; and from
the latter by the color of the spines and the fewer nectar glands. Large
spines of the vegetative branches resembling the horns of a bull, subterete,
widely spreading or incurved, sometimes fascicled and interlocking as in
A. spadicigera, but never polished, at first pale brown or olivaceous, in
age chestnut-colored or, when dead, grayish brown, the largest 8 to 10 cm.
long, 1.8 cm. broad at the base. Spikes borne on axillary flowering
branches like those of A. spadicigera, often subsessile, solitary or gemi-
nate, subtended by small leaves, these with subulate stipular spines;
peduncles puberulent, 2 to 5 mm. long, 3 mm. thick, with 4-toothed basal
involucel like that of A. spadicigera. Flowers before anthesis covered
by the laminae of the bracteoles, these lanceolate, very long-acuminate,
peltate, scabrous on the upper surface, the margin bearing a fringe of
minute straight hairs, the pedicels usually somewhat hirtellous with
fine white diaphanous hairs visible under the microscope; apices of the
* Acaciae americanae cornigerae siliquis in spinam abeuntibus. See Hermann,
Paul. Paradisi Batavi Prodromus, p. 303. 1689.
^ The Huitzmamaxalli (*• forked-thorn") of the Aztecs, described and figured in
1576 under the name Arbor cornigera by Francisco Herndndez.
safford: myrmecophilous acacias 359
bracteoles recurved. Calyx broadly tubular, resembling that of A.
spadicigera, ferruginous, the upper portion sparsely hirtellous; corolla
barely exceeding the calyx, the aperture splitting at anthesis into 5 or 6
divisions. Fruit inflated, indehiscent, terminating in a slender sharp
beak, narrowed at the base into a stipelike neck, glabrous, smooth,
olive green when young, at length bright wine-colored. Seeds 12, in 2
series, broadly ovoid, compressed, embedded in a mass of sweetish
pulp; testa hard, smooth, dark brown. Leaves closely resembling those
of A. spadicigera, those of the vegetative branches with 7 to 12 pairs of
pinnae; elongated nectar gland on the petiole crater-like, placed at the
base of the basal pair of pinnae, sometimes with a smaller raised cylin-
drical gland below it, and rarely with a second, somewhat elongated
gland at the base of the second pair of pinnae; leaflets 17 to 29 pairs,
linear-oblong, unequal at the base, the midrib and upcurving lateral
nerves conspicuous beneath, as in A. spadicigera. Leaves of the inflores-
cence smaller; pinnae 2 to 5 pairs, the petiole bearing 1 or 2 raised glands,
a gland often present also at the base of the second pair of pinnae.
Type in the U. S. National Herbarium, no. 692170, collected in the
vicinity of Rascon, State of San Luis Potosi, Mexico, July 19 to 22, 1905,
bj^ Dr. Edward Palmer (no. 669).
4. Acacia furcella sp. nov. Related to Acacia spadicigera and A.
Hernandezii, but having polished black or dark browm, forklike spines
with subcuneiform base and erect, slightly diverging or subparallel
prongs, much abbreviated or suppressed flowering branch] ets, and spikes
crowded in clusters. Base of spines 12 to 16 mm. broad, the prongs
terete, 50 to 60 mm. long, long-acuminate at the apex. Flowers densely
crowded, resembling those oi A. spadicigera, but more densely hirtellous.
Spikes cylmdrical 30 to 40 mm. long; receptacle (axis of spike) fusiform,
6 to 8 mm. thick when mature; peduncles 10 to 14 mm. long, 2 to 4 mm.
thick; involucre basal, 4-toothed, similar to that of A. spadicigera.
Calyx ferruginous, 1.4 mm. long, 0.6 mm. broad at anthesis, thickly-
covered with minute short straight projecting hairs; corolla 4 to 6-lobed,
slightly longer than the calyx. Interfloral bracteoles brown, the laminae
ovate-acuminate, peltate, sagittate at the base, scabrous above, edged
with minute short straight marginal hairs. Fruit wanting. Leaves of
vegetative branches not observed; those of flowering branches with 3 to
5 pairs of pinnae; rachis puberulent, 4 to 6.5 cm. long; nectar glands
similar to those of A. Hernandezii; leaflets 13 to 24 pairs, 9 mm. long,
2 mm. broad, reddish brown when dry, the midrib and lateral nerves
prominent beneath as in ^. spadicigera. ^
Type in the U. S. National Herbarium, no. 692166, collected on the
shore of Lake Catemaco, southern Veracruz, Mexico, at an elevation
of 1000 feet, April 26, 1894, by E. W. Nelson (no. 427).
5. Acacia nicoyensis Schenck, Repert. Nov. Sp. Fedde 12: 360.
1913.—Bot. Jahrb. Engler 50: 463. 1914.
Type in the Berlin Herbarium, collected on the shore of the Gulf of
Nicoya, Costa Rica, in February, 1900, by A. Tonduz (no. 13538) ;
duplicate of type in the U. S. National Herbarium, no. 577752.
360 safford: myrmecophilous acacias
Section 2. Dolichocephalae
{Sphaerocephalae Schenck, in part)
Flowers in spheroid or oblong heads having a thick peduncle and ovoid
or oblong receptacle; interfloral bracteoles with glabrous pedicels and
ovoid, obtuse, usually ciliate laminae. Leaflets usually with only the
midrib conspicuous beneath. Nectar glands of the petiole resembling
those of the Spadicigerae.
6. Acacia sphaerocephala Schlecht. & Cham. Linnaea 5: 594. 1830;
not Acacia sphaerocephala Benth. Trans. Linn. Soc. London 30^ : 514. 1875.
Type in the Berlin Herbarium, collected at Actopan, State of Veracruz,
Mexico, in March, 1820, by Schiede (no. 684), with flowers and leaves;
photograph and fragments of the type in U. S. National Herbarium.
7. Acacia cornigera(L.) Willd. Sp.Pl. 4: 1080. 1806 (excl. synonyms)-
Type in the Liimaean Herbarium'' from a cultivated plant growing
in the garden of George Clifford, between Haarlem and Leyden, Holland,
collected by Linnaeus (no. 4) and bearing his label, "Mimusa cornigera."
8. Acacia veracruzensls Schenck, Repert. Nov. Sp. Fedde 12:362.
1913.—Bot. Jahrb. Engler 50: 477. 1914.
Type in Herb. Mex. Schenck, collected on sand dunes south of the city
of Veracruz, Mexico, October, 1908, by H. Schenck (no. 916); fragments
of the type in the U. S. National Herbarium.
GROUP IL GLOBULIFERAE
(Sphaerocephalae Schenck, in part)
Pericarp dehiscent, coriaceous or woody, more or less compressed,
sometimes very long and slender, opening by ventral and dorsal sutures.
Flowers in long-peduncled globose heads, with spheroid receptacle.
Section 3. Ramulosae
Flower heads borne in the axils of small subulate stipular spines on
special flowering branchlets.
9. Acacia globulifera sp. nov. Flowers in small globose heads not
exceeding 5 mm. in diameter at anthesis, clustered in 2's or 3's on solitary
axillary branchlets 4 to 6 cm. long; peduncles in each cluster graduated in
length, the longest at anthesis about twice as long as the diameter of
the head; receptacle spheroid or broadly ovoid, not sharply constricted
^The writer is indebted to Dr. Alfred Barton Rendle of the British Museum of
Natural History for a photograph of the type of Acacia cornigera Willd. A(^L.)
careful comparison of this with photographs and portions of the types of A.
spadicigera and A. sphaerocephala proves that Linnaeus's original plant is speci-
fically distinct from both. It resembles an Acacia collected on the shore north
of the city of Veracruz, January 24, 1906, by Dr. J. M. Greenman (no. 87), allied
to A. sphaerocephala Schlecht. and Cham., but differing from that species in its
extrafloral nectaries and in the shape of the flower heads.
safford: myrmecophilous acacias 361
at its union with the thickened upper extremity of the peduncle. Flowers
about 2.2 mm. long when mature, funnel-shaped, the calyx with usually
5 shallow^ rounded lobes, glabrous near the base, puberulous about the
margin; corolla about one-fourth longer than the calyx and distinctly
separate from it, usually acutely 6-lobed, coarsely puberulent outside.
Interfloral pedicelled bracteoles with orbicular peltate laminae. These
subentire or the margin shallowly and obtusely toothed. Fruit not
observed. Large spines ivory white or ecru, V-shaped or spreading
like the horns of an ox, terete, 4 to 5 cm. long, 7 mm. broad at the
base. Small spines of the flowering branchlets acicular or subulate,
7 mm. long. Vegetative leaves with 6 to 10 pairs of pinnae, the rachis
6 cm. long or less (in the type material), puberulent, bearing a row of 2
to 7 conoid nectar glands below the basal pair of pinnae, the glands
having a porelike openmg surromided by a smooth, whitish, circular or
elliptical, annular margin; pinnae 15 mm. long or less; leaflets of the
longer pinnae 18 to 26 pairs, 3.5 mm. long, 0.8 mm. broad, drying dark
green. Leaves of the flowering branchlets much smaller, with 2 to 4
porelike glands at the base of the rachis and occasionally a gland at
the apex; pinnae 2 to 5 pairs, consisting of 6 to 12 pairs of leaflets.
Type in the herbarium of the Field Museum of Natural History, no.
58707, collected at the port of Silam (Tsilam), north coast of Yucatan,
April, 1895, by Dr. G. F. Gaumer (no. 1909). A second specimen from
the same locality is m the same museum, no. 36458, collected by Gaumer
(no. 655), apparently at the same time and from the same plant. Pho-
tographs and fragments of the type are in the U. S. National Herbarium.
10. Acacia Donnelliana sp. nov. Closely related to the preceding,
but easil}' distinguished by its dark-colored polished spines and much
longer vegetative leaves. Flower heads globose, long-peduncled, borne
in clusters on special flowering branchlets very much as in A. globulifera,
but with relativeh' longer and more slender peduncles, the diameter of the
heads at anthesis 8 mm., length of longest peduncles 20 mm. Flowers
and interfloral bracteoles also much as in the latter species. Fruit not
observed. Large spines V-shaped, terete, 40 mm. long, sharply acumi-
nate, those of the type material blackish or dark mahogany-colored,
polished. Small spines subtendmg the flower clusters acicular, much like
those of A. globulifera, 5 to 7 mm. long. Vegetative leaves with 14 to
18 pairs of pinnae, these 42 to 52 mm. long, composed of 30 to 40 pairs of
approximate leaflets; leaflets linear-oblong, very unequal at the truncate
base, rounded or subacute at the apex, slightly curved, dark reddish or
bronze w^hen diy; leaf rachis 10 to 20 cm. long, puberulent, bearing
at its base 4 conoid nectar glands, each opening by a small elliptical pore
with a smooth reddish margin, and in addition to these a similar gland
at the base of each pair of pinnules. Leaves of flowering branches with
several pores at the base of the rachis and a pore at the base of each of
the 6 to 15 pairs of pinnae; these leaves sometimes rudimentary or even
lacking, in such cases the flower clusters subtended by a pair of small
V-shaped acicular spmes.
362 safford: myrmecophilous acacias
Type in the herbarium of Captain John Donnell Smith, collected at
San Pedro de Sula, Department of Santa Barbara, Honduras, alt. 600
feet, March, 1888, by Dr. Carl Thieme (no. 5216); photograph of type in
U. S. National Herbarium.
Section 4. Glomeratae
Flower heads crowded in clusters in the axils of large forked or horn-
like stipular spines. Basal nectar gland solitary, much elongate, sunk
in the grooved rachis.
11. Acacia Cookii Safford, Science, N. S. 31:677. 1910.
Type in the U. S. National Herbarium, collected at the Finca Trece
Aguas, near Secanquim, Alta Verapaz, Guatemala, March 8, 1907, by
G. P. Goll (no. 102), supplemented by specimens in alcohol from the same
region, collected by O. F. Cook.
12. Acacia bucerophoraB. L. Robinson, Proc. Am. Acad. 49: 502. 1913.
Type in the Gray Herbarium, collected in British Honduras, in 1907,
by Prof. Morton E. Peck (no. 632). Photograph and fragments of the
type are in the U. S. National Herbarium.
GROUP III. LEGUMINIFERAE
(Spicatae Schenck)
Pericarp dehiscent along both the ventral and the dorsal sutures,
coriaceous or woody, relatively short; seeds embedded in a mass of pulp-
like aril. Flowers crowded in long spikes on a linear axis, this thicker
than the peduncle. Extrafloral nectar glands beadlike, with a round
central pore, often present on the rachises of the terminal pinnae as well
as upon the petiole of the leaf, but not at the base of each pair of pinnae.
Section 5. Orthocarpae
Pods straight, abruptly pointed or obtuse, tumid or subterete; seeds
alternate in 2 rows. Spines usually slender, straight or curved, slightly
broadened and compressed at the base.
13. Acacia yucatanensis Schenck, Repert. Nov. Sp. Fedde 12:361.
1913.—Bot. Jahrb. Engler 50:468. 1914.
Type in the Berlin Herbarium, collected in the forest near Chichen
Itza, Yucatan, in May, 1911, by Caec. and Ed. Seler (no. 5549 [470]).
14. Acacia Collinsii Safford, Science, N. S. 31:677. 1910.
Type in U. S. National Herbarium, no. 692159, collected between
Chicoasea and San Femandino, State of Chiapas, southern Mexico,
January 14, 1907, by G. N. Collins (no. 180).
Section 6. Acinaceae
Pods scimitar-shaped, or straight along the dorsal and curved along
the ventral suture, the apex more or less retrocurved, usually compressed
safford: myrmecophilous acacias 363
lateral!}''; seed? in a single row. Spines more or less flattened and
broadened at the base, lunate or broadly subdeltoid.
15. Acacia Nelsonii sp. nov. Plant with leaves much like those of
A. Collinsii, but easily distinguished from that species by its light-
colored, broadly spreading, upcurved, more or less flattened stipular
spines, these about 4 cm. long, 10 mm. broad at base, sometimes lunate or
IjTe-shaped, smooth, pale olivaceous to tan-colored or buff, with reddish
browTi tips, becoming gray or whitish when dead. Small spines on
flowering branchlets 2 mm. long. Vegetative leaves with 4 to 8 pairs of
pinnae; rachis 7 to 12 cm. long, without interpinnal nectar glands but
with a row of 3 or 4 glands at the base; pinnae 4.5 to 5.5 cm. long, the
leaflets 14 to 19 pairs, uniformly brown when dry, linear-oblong, 8 to
10 mm. long, 2.8 mm. broad, those bearing apical bodies at length retuse
or truncate; rachis of pinnae sometimes with a minute solitary terminal
gland at the base of the uppermost pair of leaflets. Leaves of flowering
branchlets with 1 to 5 pairs of pinnae; rachis bearing at its base a row of
3 glands. Flower spikes 32 to 36 mm. long, including the peduncle, the
latter 11 to 13 mm. long, about equal in thickness to the axis of the
spike. Interfloral pedicelled bracteoles with orbicular peltate laminae,
these imbricated over the flowers before anthesis like the scales of a
fish, after anthesis their margins everted and concealed by the mass of
anthers. Flowers tubular-funnelform, obovoid, or broadly subcylin-
drical; calyx 1.2 to 1.3 mm. high, subentire or obtusely 4 or 5-lobed;
corolla one-fourth to one-third longer than the calyx, acutely 5 or 6-
lobed, the divisions sometimes irregularly cleft; stamens very numerous,
the filaments flesh-colored, the anthers straw-colored; style filiform.
Legumes small, 2-valved, at length dehiscent by ventral and dorsal
sutures, glabrous, dark bro-wn or blackish, compressed, nearly straight
along the dorsal suture, curved along the ventral suture, tapering at
the base and slightly retrocurved at the apex. Seeds ovoid or elliptical,
somewhat compressed but not flattened; testa hard, smooth, dark brown.
Tj^pe in the U. S. National Herbarium, no. 399366, collected at Aca-
pulco. State of Guerrero, Mexico, April 30, 1903, by E. W. Nelson (no.
7024), with flowers and fruit. Cotype in the same herbarium, no.
692158, collected in the same locality, in 1895, by Dr. Edward Palmer
(no. 390a), without flowers and with a single legume.
16. Acacia costaricensis Schenck, Repert. Nov. Sp. Fedde 12: 36 1>
1913.—Bot. Jahrb. Engler 50:465. 1914.
Type in the Berlin Herbarium, collected near Lepanto, Costa Rica, in
Januarj^, 1857, by Dr. Carl Hoffmann (no. 275), without fruit. Speci-
mens collected by C. Wright in Nicaragua (U. S. North Pacific Explor.
Exped. 1853-56), cited by Schenck as conspecific, are in the Grisebach
Herbarium at Gottirigen, the Gray Herbarium, and the U. S. National
Herbarium (no, 692165), the last with broad flat pods terminating in a
sharp retrocurved point.
17. Acacia penonomensis sp. nov. Closely related to Acacia costaric-
ensis, but with falcate pods, spikes of pale yellow flowers borne on very
364 saffokd: myrmecophilous acacias
slender pulverulent peduncles, and relatively broader and shorter leaflets
with minute marginal hairs. Spikes before anthesis covered with the
pale flesh-colored, scalelike, imbricated, suborbicular limbs of the pedi-
celled interfloral bracteoles, after anthesis bright lemon yellow from the
mass of stamens, 23 to 26 mm. long, 4 to 5 mm. thick, the axis not exceed-
ing in thiclaiess the slender peduncle, this straight and rigid, about 8 mm.
long and 0.5 mm. thick, pale brownish, clothed with white puberulence,
and bearing a 4-toothed basal involucel this, puberulent outside. Flowers
crowded; calyx flesh-colored, broadly ovoid or ellipsoid, inflated, 1.25 mm.
high, 1 mm. broad, minutely puberulent about the margin, obscurely
6-lobed or subentire; corolla pale yellow, puberulent, 6-lobed, exceeding
the calyx by about one-fourth its length; filaments and anthers pale
yellow; style filiform. Legume 2-valved, dehiscent by both dorsal and
ventral sutures, curved, compressed, 4.5 cm. long, 1 cm. broad, tapering
at the base into a stipe like neck, terminating at the apex in a point.
Seeds about 12, in a single row, embedded in a sulphur-yellow pulpy
aril, broadly ovoid, 5 mm. long, 4 mm. broad, somewhat compressed into
a thick oblique ovoid disk, the testa hard, smooth, glossy dark brown.
Large stipular spines reddish bro\\ai, becoming blackish, broadly
V-shaped or deltoid, 2.6 to 3.2 cm. long, 9 to 11 mm. broad at the base,
this inflated and usually compressed, the apex abruptly acuminate
and terminating in a very slender, fine point. Spines of the flowering
branchlets minute, subulate. Vegetative leaves not observed. Leaves
of the flowering branches sometimes rudimentary, the perfect ones com-
posed of 1 to 6 pairs of pinnae; rachis pubescent, 3 to 4.5 cm. long, without
interpinnal glands, but with 1 to 3 contiguous pubescent porelike basal
glands and usually a similar but smaller terminal gland on the pubescent
rachises of the pinnae just beneath the last pair of leaflets, very much as
in A. Collinsii. Leaflets oblong-obovate, fringed with short hairs.
Type in the Herbarium of the New York Botanical Garden; duplicate
in U. S. National Herbarium, no. 677927, collected in the vicinity of
Penonome, Panama, February 23 to March 22, 1908, by R. S. Williams
(no. 113).
GROUP IV. FOLLICULARES
Pericarp a follicle, dehiscing by a single suture; seeds in a single row.
Leaf rachis with a beadlike nectar gland at the base of each pair of
pinnae; nectar glands of the petiole 1 to several, or wanting.
Section 7. Bursariae Schenck
Large stipular spines of vegetative branches much flattened and very
broad, their bases connate and pocket-like, often resembling an inverted
bicome chapeau. Flowers distinct, not closely crowded, forming a lax
linear spike with a slender, often flexible rachis. Pods slender, falcate or
curved, compressed, the seeds approximate, inclosed in a thin, whitish
or brownish, feltlike aril.
safford: myrmecophilous acacias 365
18. Acacia Hindsii Benth. Lond. Joum. Bot. 1: 504. 1842.
Tj'pe in the Kew Herbarium, collected on the shore of ManzanilJo
Bay, State of Colima, Mexico, 1836-39, by Dr. Richard B. Hinds, Sur-
geon of H. M. S. Sidphw (no. 248).
19. Acacia bursaria Schenck, Repert. Nov. Sp. Fedde 12: 363. 1913.
—Bot. Jahrb. Engler 50: 485. 1914.
Tj'pe in the Berlin Herbarium, collected near San Felipe, Guatemala,
February, 1878, by I^emouilli and Carlo (no. 1129).
20. Acacia sinaloensis sp. nov. Closely related to A. Hindsii Benth.
and .4. bursaria Schenck, but distinguished by its lighter-colored, broadly
V-shaped or Y-shaped spines, these alternate, regularly disposed at
intervals of 3 or 4 cm. along the slender, straight, terete, glabrous, reddish
bro^^^l branches; length of spines 30 to 40 mm., breadth along the suture
formed by the connate flattened bases 12 to 14 mm.; extremities terete,
tapering into a very sharp point; color of spines usually olivaceous or
yellowish green, turning bro"\Aaiish or buff-colored when old and dead.
Vegetative leaves fernlike, elliptical or oblong in outline; main rachis
grooved above, sparsely pubescent (under the microscope), bearing a
raised porelike gland at the base of each pair of pinnae; base of the
rachis (petiole) with 1 to 3 similar glands; pirniae 12 to 18 pairs, linear,
approximate, their rachises 30 to 34 mm. long, sparsely pubescent;
leaflets 5.2 mm. long, 1.4 mm. broad, thin and membranaceous when
3'oung, at length subcoriaceous, manj- of them bearing caducous amber-
colored apical bodies, those without the latter acuminate at the apex,
the margins of the leaflets bearing very short fine hairs (under the
microscope) from the base to the apex, the base very obhque, the midrib
conspicuous beneath, the lateral nerves scarcely visible even with the
microscope. Leaves of the small axillary branchlets smaller, with fewer
pairs of pinnae, these composed of fewer, relatively broader, more rounded
leaflets, their rachises provided at the base with a pair of subulate
stipular spines, usually without a basal nectar gland, but with one of these
at the base of each pair of pimiae. Flowers wanting, but apparently
borne in a lax spike. Fruit a falcate or retrocurved follicle dehiscing
along the ventral suture, 11 mm. broad near the middle, acuminate at the
apex, tapering at the base; seeds 8 to 10, in a single row, embedded in a
yellowish white, thin aril, crowded and compressed, oblong or clavate,
8 or 9 mm. long, 4 mm. broad, 2 mm. thick, tapering toward the base into
a rounded point, the testa dark brown, hard and polished, with an
oblanceolate area enclosed by a raised line on each side.
Type in the U. S. National Herbarium, no. 636818, collected in the
vicinity of Villa Union, State of Sinaloa, Mexico, growing about a pond,
April 2, 1910, by Rose, Standley, and Russell (no. 13972).
Section 8. Leiocerates
Large stipular spines of vegetative branches resembling polished
subterete spreading honis, somewhat compressed at the connate bases.
Smaller spines of the very short axillary branchlets subulate. Leaf
366 safford: myrmecophilous acacias
rachis pubescent, bearing a raised nectar gland at the base of each
pair of pinnae but (in the type) none on the petiole. Pods of the same
general form as in the preceding section but broader and thicker, the
seeds enveloped in a thicker aril.
21. Acacia tepicana sp. nov. General outline of the bipinate leaves
narrowl}^ oblanceolate or oblong, the pinnae short and the leaflets
closely crowded. Rachis 6 to 8 cm. long, reddish brown, pubescent,
bearing about 14 pairs of pinnae, with a pubescent beadlike or truncate
conoid gland at the base of each pair of pinnae, but none at the base of
the petiole; pinnae 10 to 18 mm. long, the shortest ones near the base;
leaflets 9 to 17 pairs, very small, 4.5 to 6 mm. long, 1.5 mm. broad,
oblong, unequal and truncate at the base, acute or short-acuminate at
the apex, subcoriaceous, the midrib and lateral nerves inconspicuous, the
margins contiguous or overlapping and bearing minute short straight
hairs (as seen under the microscope); lowest leaflets much smaller,
sometimes rudimentary, bearing a long tapering amber-colored waxlike
apical body. Large connate stipular spines broadly V-shaped, subterete,
somewhat compressed and broadened at the base, 27 mm. long, 8 or 9 mm.
broad at the base, brown, the surface smooth and hornlike. Small spines
of the abbreviated rudimentary axillary branchlets subulate, reddish
brown. Spikes borne on very short axillary branchlets; peduncles (only
those of mature fruiting specimens observed) 8 mm. long, bearing a
])asal involucel; axis of spike not exceeding the peduncle in thickness.
Flowers not observed; interfloral bracteoles short-pedicelled, with a
circular disklike peltate limb 1.2 mm. in diameter. Pericarp coriaceous,
glabrous, without a definite dorsal suture but sometimes splitting down
the back, brown and glabrous outside, reddish and feltlike on the inner
surface, compressed, retrocurved, 13 mm. broad in the middle, narrowed
at the base into a stipelike neck, long-acuminate at the apex. Seeds 10
to 12, in a single row, ovoid, slightly compressed, about 5.2 mm. long,
4.2 mm. broad, and 4 mm. thick, approximate, embedded in a yellowish
white aril having the taste of dried apples; testa olivaceous, hard,
smooth and glossy, bearing a raised oval ridge on each side.
Type in the U. S. National Herbarium, no. 637234, collected in the
vicinity of Acaponeta, Territory of Tepic, western Mexico, April 10,
1910, by Rose, Standley, and Russell (no. 14357).
GROUP V. HEBACANTHAE
Involucel borne at or above the middle of the peduncle. Large
spines puberulent when young, never becoming smooth or polished.
Interfloral pedicelled bracteoles not peltate, but with an ovate or fan-
shaped limb with a hairy margin.
Section 9. Clavigerae
Flowers crowded in club-shaped, cylindrical, or oblong spikes, covered
before anthesis with the imbricated ovoid limbs of the pedicefled brae-
SAFFORD : MYRMECOPHILOUS ACACIAS . 367
teoles. Peduncles long, straight, slender, puberulent or hirtellous, borne
upon axillary flowering branches, solitary or clustered. Large stipular
spines straight or nearly so, widespreading, at first puberulent, except at
the smooth glossy reddish pomt, sometimes glabrate in age, but the
surface dull and never polished.
22. Acacia Standleyi sp. nov. Flower spikes club-shaped, at anthesis,
thicker at the apex than at the base, 18 to 22 mm. long, 7 to 8 mm. thick,
pubescent before anthesis; peduncles in clusters of 2 to 5, the longest
27 mm. long at anthesis, minutely pubescent below the involucel, the
latter 4-toothed, pubescent outside, situated at or above the middle of
the peduncle; axis of spike slightly thicker than the peduncle. Flowers
with pale yellowish brown or buff, broadly tubular, obtusely lobed calyx
and tan-colored, acutely 6-lobed corolla, the latter exceeding the calyx
by one-half its length; stamens very numerous, yellow; style filiform.
Large spines pubescent at first, with glabrous reddish points, at length
dull gray or blackish, 3 to 3.5 cm. long, 6 to 8 mm. broad at the base, very
widely divergent, the pair separated by a thickened ridge (the persistent
base of the petiole) adiiate to the branch. Vegetative leaves with about
25 pairs of pinnae; main rachis pubescent above, about 10 cm. long, with
1 to 3 conspicuous glands at the base and a gland just below each of the 2
or 3 terminal pairs of pinnae, these glands usually with a smooth, light
browTi, annular margin; piimae about 2.5 cm. long, those of a pair some-
times not quite opposite; rachis of pinnae pubescent above; leaflets about
30 pairs, approximate, relatively thick and coriaceous, scarcely showing
the venation even under the microscope, oblong-linear, 3.2 mm. long,
0.8 mm. broad, unequal at the base, rounded at the apex, sometimes
mucronulate or tipped with an apical body, the margin at first bearing a
frmge of minute hairs, at length glabrate. Leaves of the axillary flower-
mg branches with 4 to 8 pairs of pinnae composed of 12 to 16 pairs of
leaflets, these 2 mm. long, 0.6 mm. broad, when young fringed with
hairs, many of them tipped with apical bodies; main rachis bearing a
conspicuous annular nectar gland at the base of each pair of pinnae and
usually one on the petiole, just below the lowest of these; stipular spines
subulate, 4 mm. long.
Type in the U. S. National Herbarium, no. 637251, collected in the
vicinity of Acaponeta, Territory of Tepic, western Mexico, April 11,
1910, by Rose, Standley, and Russell (no. 14374).
23. Acacia hirtipes sp. nov. Flower spikes oblong or cylindrical, 11 to
15 mm. long, 6 mm. thick, covered before anthesis by the tomentulose
laminae of the bracteoles; peduncles densely hirtellous, in clusters of
2 or 3, 14 to 20 mm. long; mvolucel 4-toothed, hirtellous, situated above
the middle of the peduncle; axis scarcely thicker than the peduncle.
Flowers with reddish brown or tan-colored calyx resembling that of
A. Standleyi but narrower at the base and pubescent about the shallowly
lobed margui; corolla dark purple or blackish, exceeding the calyx by
one-half or three-fourths its length,, pubescent with whitish hairs around
the 5- or 6-lobed margin; filaments reddish browTi; anthers pale tan-
368 SAFFORD : MYRMECOPHILOUS ACACIAS.
colored; interfloral bracteoles tomentose on the upper surface. Fruit not
observed. Large stipular spines broadly V-shaped, cinereous, puberulent
except at the points, 3 to 4.2 cm. long, 10 mm. broad at the cuneate base,
the latter flattened but not adnate to the branch as in ^. Standleiji.
Spines of the flowering branches subulate, 3 to 6 mm. long, when young
strigose except at the polished red tips. Vegetative leaves not observed.
Leaves of the flowering branches with 5 to 12 pairs of pinnae composed of
9 to 18 pairs of leaflets, these 2.4 mm. long, 0.8 mm. broad, similar in
shape to those of A. Standleiji but with a persistent marginal fringe
of stiff short straight hairs; rachis persistently and densely hirtellous,
clothed with minute stiff whitish hairs; nectar glands dark purplish,
circular, bowl-shaped, with a thick annular magin, one in the smaller
leaves of the short branchlets one borne at the base of each pair of pinnae
and an additional one on the petiole; on the larger leaves of the longer
branches similar glands borne at the base of each pair of pinnae of the
upper half of the leaf, but none in the lower half except a solitary gland
on the petiole.
Type in the U. S. National Herbarium, no. 694036, collected on
the Rio de las Canas, Department of Santa Rosa, Guatemala, altitude
3000 feet, April, 1892, by Heyde and Lux (no. 3299, in part; mixed with
specimens of A. hursaria) under the name of ''A. spadicigera."
Acacia hirtipes is a shrub with densely cmereous-hirtellous young
growth, closely related to A. Standleyi but easily distinguished by the
dark purplish corolla, the more densely hirtellous indument of the
pedmicles and leaf rachis, and the persistent marginal hairs of the leaflets.