LEGUMINOS. SILVA OF NORTH AMERICA. 109 
LEUCANA. 
FLowers in globular heads; calyx 5-toothed, the teeth valvate in estivation ; petals 
5, valvate in estivation, free; stamens 10, free; ovary stipitate, many-ovuled. Legume 
broadly linear, plano-compressed, 2-valved. Leaves abruptly bipinnate. 
Leuczena, Bentham, Hooker Jour. Bot. iv. 416. — Meisner, Gen. pt. ii. 353. — Bentham & Hooker, Gen. i. 594. — Baillon, 
Hist. Pl. ii. 67. 
Trees or shrubs, with branches usually unarmed. Leaves alternate, persistent, bipinnate, petiolate, 
the petioles often furnished with a conspicuous gland below the lower pair of pinne; leaflets small, in 
many pairs, or few, large, and oblique; stipules setaceous, minute, or ample, deciduous, rarely becoming 
spinescent and persistent.’ Flowers white, mostly perfect, sessile in the axils of small bractlets, imbri- 
cated in globose pedunculate heads, the peduncles in axillary fascicles or in leafless terminal racemes, 
sometimes bibracteate near the apex. Calyx tubular-campanulate, minutely five-toothed, deciduous. 
Petals five, acute or rounded at the apex, narrowed at the base, hypogynous. Stamens ten, free, 
inserted under the ovary, exserted ; filaments filiform; anthers ovate, oblong, or globose, eglandular, 
attached on the back near the middle, versatile, usually pilose, two-celled, the cells opening longitu- 
dinally. Ovary stipitate, many-ovuled, contracted into a long slender style; stigma terminal, minute, 
slightly dilated ; ovules attached in two ranks on the inner angle of the ovary, superposed, anatropous, 
the micropyle superior. Legume many-seeded, stipitate, linear, compressed, tipped with the remnants 
of the style, dehiscent, the valves thickened on the margins, rigid, membranaceous, continuous within ; 
exocarp thin and papery, dark-colored, the endocarp rather thicker, woody, pale brown. Seed obovate, 
compressed, transverse, the hilum near the base; funicle long and slender; testa thin, crustaceous, 
brown and lustrous. Embryo inclosed on its two sides by a thin layer of horny albumen; cotyledons 
oval, flat, the radicle straight, slightly exserted. 
Leucena is represented by nine or ten species.” One® inhabits the islands of the Pacific Ocean 
from New Caledonia to Tahiti, and the others the warmer parts of America, where they are distributed 
from western Texas through Mexico to Lower California and to Central America, Peru, Venezuela, and 
San Domingo. Three species occur within the territory of the United States. Leucena retusa* is a 
slender shrub, abundant in some parts of Texas west of the Colorado River and reaching the borders 
of New Mexico; the others are small trees. 
Leucena is not known to possess useful properties. 
The genus was established by Bentham to receive a number of plants previously referred to Acacia, 
which they resemble in habit and in the appearance of the fruit ; this, however, in the character of the 
valves and in the albumen of the seeds approaches the fruit of Desmanthus rather than that of Acacia, 
while the flowers are similar to those of Mimosa. 
The generic name, from Agevxaiva, refers to the color of the flowers. 
1 The stipules of Leucena Greggii (Watson, Proc. Am. Acad. 8 Leucena glandulosa. 
xxiii. 272), a small tree of northern Mexico, are triangular, ovate, L. Fosteri, Bentham, Hooker Lond. Jour. Bot. v.94; Trans. Linn. 
and contracted into long slender points which become rigid and Soc. xxx. 442. 
spinescent, and remain on the branches for at least a year as slender Mimosa glandulosa, Foster, Prodr. 92. 
geminate spines, sometimes a third or nearly half an inch in length. Acacia glandulosa, Guillemin, Ann. Sci. Nat. ser. 2, vii. 360. 
There are traces of similar spinescent stipules also on Leucena 4 Bentham; Gray, Smithsonian Contrib. iii. 64 (Pl. Wright. i.) ; 
macrophylla (Bentham, Bot. Voy. Sulphur, 90). Trans. Linn. Soc. xxx. 443. — Coulter, Contrib. U. S. Nat. Herb. ii. 
2 Bentham, Trans. Linn. Soc. xxx. 444 (Rev. Mim.).—Watson, l.c. 98 (Man. Pl. W. Texas). 
