LEGUMINOS&. SILVA OF NORTH AMERICA. 137 
PITHECOLOBIUM FLEXICAULE. 
Ebony. 
FLowers perfect, in axillary spikes. Legume thick and woody, interrupted within. 
Branches armed with rigid spinescent stipules. . 
Pithecolobium flexicaule, Coulter, Contrib. U. S. Nat. Sep i. 913. — Dietrich, Syn. v. 497. — Gray, Smith- 
Herb. ii. 101 (Man. Pl. W. Texas). sonian Contrib. iii. 65 (Pl. Wright. i.); Proc. Am. Acad. 
Pithecolobium Texense, Coulter, Contrib. U. S. Nat. v. 158. — Torrey, Bot. Mex. Bound. Surv. 62. — Hems- 
Herb. No. 2, 37; Bot. Gazette, xv. 269. ley, Bot. Biol. Am. Cent. i. 353. — C. G. Pringle, Garden 
Acacia flexicaulis, Bentham, Lond. Jour. Bot. i. 505; and Forest, ii. 394.— Sargent, Garden and Forest, ii. 
Trans. Linn. Soc. xxx. 514 (Rev. Mim.).— Walpers, 400, f. 123. — Havard, Proc. U. S. Nat. Mus. viii. 499. 
A tree, twenty to thirty feet in height, with a straight trunk two or three feet in diameter, sepa- 
rating, eight or ten feet from the ground, into short spreading branches which form a wide round head. 
The branches are stout, zigzag, covered with pale lenticels and armed with persistent stipular pale 
chestnut-brown spines from a quarter to half an inch in length; when they first appear they are 
puberulous and are sometimes light green and sometimes dark reddish brown ; in their second year they 
are glabrous or rarely puberulous, and usually dark reddish brown or often light gray. The leaves are 
persistent, long-petiolate with slender puberulous petioles and rachises, with four to six pinne, an inch 
and a half to two inches long and two and a half to three inches broad. The petioles are glandular 
near the middle, and furnished at the apex with small orbicular solitary glands; the pine are six to 
twelve, usually six-foliolate, the lower pair often the shortest ; the leaflets are ovate-oblong, rounded at 
the apex, reticulate-veined, membranaceous or subcoriaceous, glabrous, dark green and lustrous on the 
upper surface and paler on the lower, from a quarter to a third of an inch in length, and borne on 
short broad petiolules. The flowers, which appear from June until August, are produced in cylindrical 
dense or interrupted spikes an inch and a half long on stout pubescent peduncles fascicled in the axils 
of the upper leaves of the previous year; they are sessile in the axils of minute caducous bracts, light 
yellow or cream color and deliciously fragrant, and with the exserted stamens are an eighth of an inch 
in length. The corolla is four or five times as long as the calyx, like this puberulous on the outer 
surface, and about as long as the tube formed by the union of the filaments. The ovary is glabrous 
and sessile. The legumes, which ripen in the autumn and remain on the branches until after the 
flowering season of the following year, are tardily dehiscent ; they are flattened, turgid, straight or 
slightly falcate, sessile, oblique at the base, rounded and contracted into a short broad point at the 
apex, four to six inches long and an inch to an inch and a quarter broad, with thick woody valves lined 
with a thick pithy substance inclosing and separating the seeds. These are suspended transversely on 
very short straight funicles, and are half an inch in length, a quarter of an inch in breadth, irregularly 
obovate and usually more or less flattened on one side; the testa is thick, crustaceous, bright reddish 
brown, and faintly marked on the two sides of the seed with a short oblong depression. 
Pithecolobium flexicaule is distributed from the shores of Matagorda Bay in Texas to the Sierra 
Madre in Nuevo Leon and has been found at La Paz in Lower California.’ It is common on the bluffs 
of the Gulf coast in Texas and on those of both banks of the lower Rio Grande, and south of the river 
is one of the commonest and most beautiful trees of the region. 
The wood of Pithecolobium flexicaule is exceedingly heavy, hard, compact, and close-grained, with 
1 Vasey & Rose, Contrib. U. S. Nat. Herb. No. 3, 69. 
