BETULACEZ. SILVA OF NORTH AMERICA. 57 
BETULA OCCIDENTALIS. 
Birch. 
STROBILES cylindrical, pendulous. Leaves ovate, acuminate, rounded or cordate at 
the broad base. 
Betula occidentalis, Hooker, #7. Bor.-Am. ii. 155 (in part) Soc. Nat. Mose. xxviii. pt. ii. 400 (Gattungen Betula und 
(1839).— Spach, Ann. Sci. Nat. sér. 2, xv. 197 (Revisio Alnus) (in part) (1865); De Candolle Prodr. xvi. pt. ii. 
Betulacearum) (in part).—Lyall, Jour. Linn. Soe. vii. 165 (in part). 
134.— Sargent, Bot. Gazette, xxxi. 237. Betula papyrifera, Macoun, Cat. Can. Pl. 436 (in part) 
Betula alba, subsp. 5 occidentalis, a typica, Regel, Bull. (1886). — Sargent, Silva N. Am. ix. 57 (in part). 
A tree, from one hundred to one hundred and twenty feet in height, with a trunk three or four 
feet in diameter, and comparatively small branches which while the tree is young are slightly ascending 
and form a narrow symmetrical pyramidal crown, and on old trees are often pendulous. The bark is 
thin, marked by large oblong horizontal dark-colored raised lenticels, light orange-brown, very lustrous, 
and separates freely into thin papery layers which disclose in fallmg the bright orange-yellow inner 
bark. The branchlets are stout, and when they first appear are pale orange-brown, more or less glandu- 
lar, and coated with long pale hairs; during their first winter they are bright orange-brown marked. by 
numerous minute pale lenticels, pubescent or puberulous, and nearly destitute of glands, and in their 
second year they are orange-brown, glabrous, very lustrous, and the lenticels begin to lengthen horizon- 
tally. The winter-buds are acute, bright orange-brown, and from one eighth to one quarter of an inch 
in length, and in expanding the inner scales, which are obovate or oblong, rounded at the apex, light 
yellow-brown, and scarious, sometimes become three quarters of an inch long. The leaves are ovate, 
acute, usually rounded but occasionally cordate or rarely cuneate at the broad base, and coarsely and 
generally doubly serrate, with straight or incurved glandular teeth; when they unfold they are light 
yellow-green covered with dark reddish resinous viscid glands and villose along the midribs and veins, 
with long white hairs which are most abundant on their lower side and in the axils of the primary veins, 
where they often form large tufts which are persistent during the summer; at maturity they are thin 
but firm in texture, marked by the scars of the fallen glands, dull dark green on the upper surface, pale 
yellow-green on the lower surface, and puberulous on both sides of the stout yellow midribs and five or 
six pairs of slender primary veins, from three to four inches long and from an inch and a half to two 
inches wide; they are borne on stout glandular grooved petioles at first tomentose, ultimately pubescent 
or puberulous, and about three quarters of an inch in length. The stipules are oblong-obovate, rounded, 
or acute and apiculate at the apex, ciliate on the margins, with short white hairs, puberulous, glandular- 
viscid, about half an inch long and from an eighth to a quarter of an inch wide. During the winter the 
staminate aments are about three quarters of an inch long and an eighth of an inch thick, with ovate 
scales rounded or abruptly narrowed and acute at the apex, puberulous on the outer surface, and ciliate 
on the margins, with long scattered pale hairs, and when they are fully grown and the flowers have 
opened in May they are from three to four inches long and about a quarter of an inch wide. The 
strobiles, which are produced on stout peduncles about three quarters of an inch long, are cylindrical, 
from an inch and a quarter to an inch and a half in length and from a quarter to a half of an inch in 
thickness ; their scales are much longer than they are broad, gradually narrowed to the base, puberulous 
on the outer surface, and ciliate on the margins, with spreading lateral lobes, and an elongated terminal 
