Leaves linear-lanceolate, narrowed at the ends, acute, slightly falcate, mucronate at the apex, entire or rarely obscurely dentate above the middle, coated as they unfold with long soft white hairs, at maturity pale gray-green, slightly puberulous, ⅓′—1⅓′ long, 1/12′—⅛′ wide, with a slender midrib, thin arcuate veins, and thickened slightly revolute margins; petioles stout, puberulous, rarely 1/12′ long; stipules ovate, acute, scarious, minute, caducous. Flowers: aments densely flowered, oblong-cylindric or subglobose, ¼′—½′ long, terminal, or terminal and axillary on the staminate plant, on short leafy branchlets; scales oblong or obovate, rounded or acute and sometimes apiculate at apex, coated on the outer surface with hoary tomentum and pubescent or glabrous on the inner; stamens 2, with free filaments hairy below the middle; ovary ovoid-conic, short-stalked or subsessile, villose, with nearly sessile deeply emarginate stigmas. Fruit cylindric, long-pointed, bright red-brown, more or less villose, short-stalked, about ¼′ long. A tree, often 40°—50° high, with a trunk 18′ in diameter, erect and drooping branches forming a broad open head, and slender branchlets 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 ovoid, acute, dark chestnut-brown, puberulous, about 1/16′ long and nearly as broad as long. Bark of the trunk ¾′—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; southwestern New Mexico, and along mountain streams in southern Arizona; southward through Mexico to Guatemala, and on the Sierra de la Victoria, Lower California. 11. Salix sessilifolia Nutt. [Illustration: Fig. 145] Leaves linear-lanceolate to elliptic-lanceolate, acute or acuminate at apex, cuneate at base, entire or furnished above the middle with a few remote apiculate glandular teeth, bluish green and thickly covered with silky white hairs most abundant on the lower side of the midrib, 1′—2′ long, ½′—¾′ wide, or on vigorous summer shoots often 4′ long and 1¼′ wide; petioles densely villose-pubescent, 1/16′—⅛′ in length; stipules ovate to lanceolate, acute, entire or denticulate. Flowers: aments appearing after the leaves, terminal on leafy branchlets, densely hoary-tomentose, 1½′—2½′ long; scales broadly elliptic, acute or rounded at apex, cuneate at base, densely villose-tomentose; stamens 2; filaments villose below the middle; ovary sessile, villose, the stigmas sessile, deeply 2-lobed. Fruit ovoid-acuminate, densely villose, pubescent. A shrub or small tree occasionally 20° high, with short hairy tomentose branchlets. Distribution. River banks, southwestern British Columbia; Whitcomb County, Washington, and on the Umpqua and Willamette Rivers, western Oregon. Southward passing into