LEGUMINOSS. SILVA OF NORTH AMERICA. 113 
LEUCAINA PULVERULENTA. 
Mimosa. 
BRANCHLETS pulverulent-tomentose. Peduncle ebracteolate. Leaves 30 to 36- 
pinnate, the pinne 60 to 120-foliolate. 
Leuceena pulverulenta, Bentham, Hooker Lond. Jour. Pringle, Garden and Forest, ii. 393. — Coulter, Contrib. 
Bot. iv. 417 ; Trans. Linn. Soc. xxx. 443 (Rev. Mim.). — U.S. Nat. Herb. ii. 98 (Man. Pl. W. Texas). 
Dietrich, Syn. v. 477. — Hemsley, Bot. Biol. Am. Cent. Acacia pulverulenta, Schlechtendal, Linnea, xii. 571. 
i, 351.—Sargent, Forest Trees N. Am. 10th Census Acacia esculenta, Martens & Galeotti, Bull. Acad. ruc. 
O. S. ix. 63; Garden and Forest, ii. 388, f. 122. —C. G. x. pt. ii, 312. 
A tree, fifty or sixty feet in height, with a straight trunk eighteen or twenty inches in diameter, 
separating, twenty or thirty feet from the ground, into slender spreading branches which form a loose 
round handsome head. The bark of the trunk is a quarter of an inch thick, bright cinnamon-brown, 
and roughened with thick persistent scales. The branchlets when they first appear are more or less 
striately grooved, and are thickly coated with pulverulent tomentum which, however, soon disappears, 
and at the end of a few weeks they become terete, pale cinnamon-brown, and only slightly puberulous. 
The leaves are from four to seven inches long and three or four inches broad, with fifteen to eighteen 
pairs of pinnae, slender petioles usually marked with a large dark oblong gland between the somewhat 
enlarged base and the lowest pair of pinne, and minute caducous stipules. When the leaves unfold 
they are covered, like the peduncles and flower-buds, with dense hoary tomentum, and at maturity are 
puberulous on the petioles and rachises. The leaflets are linear, acute at the apex, rather oblique at 
the base by the greater development of the upper side, sessile or very short-petiolulate, pale bright green, 
and from a sixth to a quarter of an inch in length. The flower-heads, which are half an inch or rather 
more in diameter, appear in succession, as the branches grow, from early spring to midsummer, and are 
borne on slender peduncles an inch or an inch and a half in length fascicled in the axils of the upper 
leaves of the branchlets, which, when the tree is in flower, thus appear to terminate in leafy racemes one 
or two feet long. The flowers are produced from the axils of minute clavate scarious bractlets. The 
calyx is slightly five-toothed and a quarter as long as the acute petals, which, like these, are pilose on 
the outer surface. The stamens are twice the length of the petals, with glabrous oblong anthers. The 
ovary is coated with long pale hairs. The legumes, which are of different lengths and produced two or 
three together on a common peduncle thickened at the apex, are conspicuously thick-margined, four to 
fourteen inches in length, long-stalked, and tipped with short straight or recurved points. The seeds 
are five sixteenths of an inch long with a dark lustrous coat. 
Leucena pulverulenta grows in Texas for a few miles along the Rio Grande near its mouth ; it 
is more abundant from Matamoras to Monterey in Nuevo Leon, and has also been collected in Mexico 
on the banks of the Misantla River near San Antonio, at Orizaba and Cordova and near the City of 
Mexico. In the valley of the lower Rio Grande Leucena pulverulenta is not common, being found 
only in a few places on the banks of the river or on the borders of lagoons and small streams, always 
growing in rich moist soil, and usually associated with the beautiful Texas Elm, which hardly over- 
tops it. 
The wood of Leucena pulverudenta is heavy, hard, and very close-grained, and contains numerous 
thin conspicuous medullary rays, and many small regularly distributed open ducts. It is rich dark 
brown, with thin clear yellow sapwood composed of two or three layers of annual growth. The specific 
gravity of the absolutely dry wood is 0.6732, a cubic foot weighing 41.95 pounds. It is considered 
