112 SILVA OF NORTH AMERICA. LEGUMINOSE. 
Leucena glauca is probably a native of the warmer parts of the New World; but it has been 
cultivated so long and has now established itself so firmly in most of the tropical countries of both 
hemispheres that its origin is uncertain. It occurs in western Texas from San Saba to the valley of 
the Devil’s River in many localities so remote from human habitations that it hardly seems possible it 
could have reached them through the agency of man. It is widely scattered through Mexico and 
Central America,’ and many of the countries of South America, extending at least as far south as 
southern Brazil.2 It has become naturalized in most of the West India and Bahama Islands* and on 
Key West in Florida,* and is now common in tropical Africa’ and Asia,° and on the islands of the 
Pacific Ocean.”. In Texas and northern Mexico Lewcena glauca inhabits dry rocky hillsides and the 
sides of depressions in the desert, or is occasionally found near the borders of small streams. 
The wood of Leucena glauca is heavy, hard, and close-grained, and contains many small regularly 
distributed open ducts. The layers of annual growth and the medullary rays are hardly distinguishable. 
It is rich brown streaked with red, with thin clear yellow sapwood. The specific gravity of the abso- 
lutely dry wood is 0.9235, a cubic foot weighing 57.55 pounds. 
Leucena glauca appears to have been first described in 1690 by Kiggelaer* in his catalogue of 
the plants cultivated in the garden of Simon van Beaumont, of Dordrecht,’and in the same year was in 
cultivation in the gardens of Hampton Court.° The beauty of its large pale finely divided leaves, its 
showy heads of flowers produced in the tropics throughout the year, and its handsome fruit, must early 
have made Leucena glauca a favorite garden plant in many warm countries where its vigorous consti- 
tution, the ability of its seeds to germinate under trying conditions, and its rapid growth have enabled 
it to secure a foothold and gradually spread itself over wide areas. 
1 Hemsley, Bot. Biol. Am. Cent. i. 351. Acacia, Buxi foliis rotundioribus, floribus albis, siliqua lata com- 
? Bentham, Martius Fl. Brasil. xv. pt. ii. 391. pressa, Catesby, Nat. Hist. Car. ii. 42, t. 42. 
8 Grisebach, Fl. Brit. W. Ind. 220. — Sauvalle, Fl. Cub. 35. Mimosa arborescens Americana non spinosa, pinnis Acacie latiori- 
4 Chapman, Fi. ed. 2, Suppl. 619. bus inferne glaucis, flore albo, Breyn, Prodr. ed. 1739, 83. 
5 Oliver, Fl. Trop. Afr. ii. 337. Mimosa inermis, foliis duplicato-pinnatis : partialibus utrinque senis 
§ Wight & Arnott, Prodr. Fl. Ind. 276.— Bentham, Fl. Hongk. pluribusve, siliquis planis membranaceis, Royen, Fl. Leyd. Prodr. 472. 
100. — Hooker f. Fl. Brit. Ind. ii. 290. Acacia non spinosa, flore albo, foliorum pinnis latiusculis glabris, 
7 Hillebrand, Fl. Haw. Js. 114. siliquis longis planis, Miller, Dict. Icon. 4, t. 4.— Trew, Pl. Ehret, 9, 
8 Acacice similis Americana non spinosa, floribus globosis albis ra-  t. 36. 
mosis, 3. 9 Aiton, Hort. Kew. iii. 441. — Loudon, Arb. Brit. ii. 665. 
EXPLANATION OF THE PLATE. 
Puate CXXXIX. Lerucmna GLauca. 
1. A flowering branch, natural size. 
2. Diagram of a flower. 
2%. A flower-bud with its bractlet, enlarged. 
A flower, enlarged. 
A stamen, enlarged. 
A pistil, enlarged. 
Vertical section of an ovary, enlarged. 
An ovule, much magnified. 
OAR AP w& 
A portion of a legume, one of the valves removed, natural size. 
9. Vertical section of a seed, natural size. 
10. Cross section of a seed, enlarged. 
11. An embryo, magnified. 
