792 



TREES OF NORTH AMERICA 



oblong; seed-coat thin, light brown, longitudinally veined, produced into broad lat- 

 eral wings divided at their rounded ends into long fringes of thin soft white hairs; 

 cotyledons plane, broader than long, slightly 2-lobed and rounded laterally; radicle 

 short, erect, turned toward the oblong basal hilum. 



The genus is represented by a single species, a native of the region adjacent to the 

 boundary between the United States and Mexico. 



The generic name, from x ^ os and <tyis, is without special significance. 



1. Chilopsis linearis, DC. Desert Willow. 



Leaves unfolding in early spring, 6'-12' long and '-' wide, deciduous during 

 the following winter. Flowers appearing in early summer in racemes 3'^4' long 

 and continuing to open for several months in succession, 1^' long and about l\ r across 

 the expanded lobes of the corolla. Fruit ripening in the autumn, 7'-12' long, ^' thick 

 in the middle, persistent on the branches during the winter; seeds ^' long and ^' wide. 



A tree, 20-30 high, with a trunk usually more or less reclining, often hollow, 

 and sometimes a foot in diameter, slender upright branches forming a narrow head, 

 and branchlets glabrous or covered with dense tomentum when they first appear, 



light chestnut-brown during their first season, later becoming darker and tinged with 

 red, or sometimes ashy gray; or often a straggling shrub. Bark of the trunk \'-%' 

 thick, dark brown and divided into broad branching ridges broken on the surface 

 into small thick plate-like scales. Wood soft, not strong, close-grained, brown 

 streaked with yellow, with thin light-colored sapwood of 2 or 3 layers of annual 

 growth. 



Distribution. Banks of streams, and depressions in the desert, usually in dry 

 gravelly porous soil; valley of the lower Rio Grande, through western Texas, south- 

 ern New Mexico, Arizona, southern Utah and Nevada, to San Diego County, Califor- 

 nia, and northern Mexico. 



Occasionally cultivated as an ornamental plant in the southern states, and in Mexico. 



2. CATALFA, Scop. 



Trees, with stout terete branchlets with thick pith, without terminal buds, minute 

 globose axillary buds nearly immersed in the bark and covered by numerous scales, 



