178 



TREES OF NORTH AMERICA 



A tree, often 40-50 high, with a trunk 18' in diameter, erect and drooping 

 branches forming a broad open head, and slender brauchlets covered during their 

 first season with hoary tomentum, becoming light reddish or purplish brown and 

 much roughened by the elevated persistent leaf-scars. Winter-buds ovate, acute. 



dark chestnut-brown, puberulous, about ^' long and nearly as broad as long. Bark 

 of the trunk |'-1' thick, light gray-brown, and divided by deep fissures into broad 

 flat ridges covered by minute closely appressed scales. 



Distribution. Near El Paso, Texas, and along mountain streams in southern Ari- 

 zona, southward through Mexico to Guatemala, and in Lower California. 



2. Scales of the aments dark-colored at the apex; stamens 2. 

 *Capsule glabrous. 



11. Salix balsamifera, Barr. Willow. 



Leaves involute in the bud, ovate to ovate-lanceolate, acute or acuminate, broad 

 and rounded and usually subcordate at the base, finely serrate, with glandular teeth, 

 balsamic particularly while young, when they unfold thin, pellucid, red and coated 

 below with long slender caducous hairs, at maturity thin and firm, dark green above, 

 pale and glaucous below, 2'-4' long, I'-l^' wide, with yellow midribs and conspicuous 

 reticulate veinlets; their petioles reddish or yellow, \'-\' long; stipules often want- 

 ing or on vigorous shoots foliaceous, broadly ovate and acute. Flowers: aments 

 cylindrical, !'-!' long, on long slender leafy branches; their scales obovate, acute, 

 rose-colored, coated with long white hairs; stamens 2, with free filaments and reddish 

 ultimately yellow anthers; ovary narrow, long-stalked, gradually contracted above the 

 middle, with nearly sessile emargiuate stigmas. Fruit ovate-conical, long-stalked, 

 \' long, dark orange color. 



Usually a shrub, often making clumps of crowded slender erect stems generally 

 destitute of branches except near the top, rarely arborescent, with a height of 25, a 

 trunk 12'-1-1' in diameter, erect branches, and comparatively stout reddish brown 

 branchlets becoming olive-green in their second year and marked with narrow 

 slightly raised leaf-scars. Winter-buds acute, much-compressed, bright scarlet, 

 very lustrous, about \' long. Bark thin, rather smooth, dull gray. 



