[Illustration: Fig. 148] Leaves oblanceolate to lanceolate-oblong, often inequilateral and occasionally falcate, acute or acuminate or rarely rounded at apex, gradually or abruptly cuneate or rounded at base, entire or remotely serrate, pilose above and coated below with thick hoary tomentum when they unfold, at maturity thick and subcoriaceous, conspicuously reticulate-venulose, dark green and glabrous above, pale or glaucous and pubescent or puberulous below, 3′—6′ long, ½′—1′ wide, with a broad yellow midrib and slender arcuate veins forked and united within the slightly thickened and revolute margins; petioles slender, ⅛′—½′ long; stipules ovate, acute, coated with hoary tomentum, minute and caducous, or sometimes foliaceous, semilunar, acute or acuminate, entire or denticulate, dark green above, pale below, persistent. Flowers: aments erect, cylindric, slightly flexuose, densely flowered, nearly sessile on short tomentose branchlets, 1½′ long, the staminate ½′ thick, and nearly twice as thick as the pistillate; scales oblong-obovate, rounded or acute at the apex, dark-colored, clothed with long crisp white hairs, persistent under the fruit; stamens 2, with elongated glabrous filaments more or less united below the middle; ovary narrow, cylindric acute and long-pointed, dark green, glabrous, with a short style and broad nearly sessile stigmas. Fruit oblong-cylindric, light reddish brown, about ¼′ long. A tree, 20°—35° high, with a trunk 3′—7′ in diameter, slender erect branches forming a loose open head, and stout branchlets coated at first with hoary tomentum, bright yellow or dark reddish brown and puberulous or pubescent during their first year, becoming darker and glabrous in their second season; or often at the north and at high altitudes a low shrub. Winter-buds ovoid, acute, compressed, contracted laterally into thin wing-like margins, light brownish yellow, glabrous or puberulous. Bark on young stems and on the branches thin, smooth, light gray-brown, becoming on old trunks dark, about ⅓′ thick, roughened by small lenticels and broken into broad flat irregularly connected ridges. Wood light, soft, close-grained, light brown, with thick nearly white sapwood; in southern California often used as fuel. Distribution. Banks of streams in low moist ground; valley of the Klamath River, California, southward along the foothills of the Sierra Nevada, the central valley, and on the Coast Ranges to southern California; on Santa Catalina Island and on the mountains of southern Arizona; on the Sierra de Laguna, Lower California; occasionally ascending to altitudes of 4000° above the sea. 15. Salix Mackenzieana Barr. [Illustration: Fig. 149]