Leaves ovate, acute or acuminate, broadly cuneate or somewhat rounded at the entire base, irregularly coarsely often doubly serrate, glabrous, dark dull green above, pale yellow-green below, 1½′—2′ long, 1′—1¾′ wide, with a slender yellow midrib and 5 pairs of thin primary veins; petioles slender, ¾′—1′ long. Flowers: staminate aments clustered, 1′ long, with ovate acute scales apiculate at apex, puberulous on the outer surface; pistillate aments, ⅓′—½′ long, about 1/16′ thick, on slender glandular pubescent peduncles ½′—¾′ in length; scales acuminate light green strongly reflexed; styles bright red. Fruit: strobiles cylindric, glabrous, 1′ long, their scales ciliate on the margins; nut oval, somewhat narrower than its thin wing. A tree, 30°—40° high, with a trunk 12′—20′ in diameter, wide-spreading branches, stout branchlets marked by numerous small pale lenticels, bright red-brown during 2 or 3 years, gradually becoming darker. Bark thin, more or less furrowed, very dark brown or nearly black near the base of the trunk, grayish white or light reddish brown and separating into thin layers higher on the stem and on the branches. Distribution. Coast of Alaska from Cook Inlet southward to the head of the Lynn Canal. 7. Betula alaskana Sarg. White Birch. [Illustration: Fig. 205] Leaves rhombic to deltoid-ovate, long-pointed, truncate, rounded or broadly cuneate, or on leading shoots occasionally cordate at the entire base, coarsely and often doubly glandular-serrate, thin, dark green above, pale and yellow-green below, 1½′—3′ long, 1′—1½′ wide, with a slender midrib and primary veins pubescent or ultimately glabrous below; petioles often bright red, somewhat hairy at first, finally glabrous, about 1′ long; Flowers: staminate aments clustered, sessile, 1′ long, ⅛′ thick, with ovate acuminate scales puberulous on the outer surface, and bright red, with yellow margins; pistillate aments slender, cylindric, glandular, 1′ long, ⅛′ thick, on stout peduncles nearly ½′ in length. Fruit: strobiles glabrous, pendulous or spreading, 1′—1¼′ long, ⅓′—½′ thick, their scales ciliate on the margins; nut oval, narrower than its broad wing. A tree, usually 30°—40°, occasionally 80°, high, with a trunk 6′—12′ in diameter, slender erect and spreading or pendulous branches, and glabrous bright red-brown branchlets more or less thickly covered during their first year with resinous glands sometimes persistent until the second or third season. Winter-buds ovoid, obtuse at the gradually narrowed apex, about ¼′ long, with light red-brown shining outer scales sometimes ciliate on the margins, and oblong rounded scarious inner scales hardly more than ½′ long when fully grown. Bark thin, marked by numerous elongated dark slightly raised lenticels, dull reddish brown or sometimes nearly white on the outer surface, light red on the inner surface, close and firm, finally separable into thin plate-like scales.