SALICACE^ 159 



In the northeastern United States and in Canada a form of this tree, var. candi- 

 cans, Gray, Balm of Gilead, is frequently cultivated as a shade-tree and has some- 

 times escaped and become spontaneous. It differs from the common form in its 

 more spreading branches, forming a broader and more open head, in its broader 

 cordate coarsely serrate leaves, with gland-tipped teeth, more or less pubescent 

 when young and at maturity paler on the lower surface, ciliate on the margins, with 

 short white hairs and usually pubescent along the principal veins, and in its pubes- 

 cent petioles and rather heavier wood; of uncertain origin, probably not indigenous 

 in New England or eastern Canada. 



5. Populus angustifolia, James. Narro"w-leaved Cotton-wood. 



Leaves lanceolate, ovate-lanceolate or rarely obovate, narrowed to the tapering- 

 acute or rounded apex, gradually narrowed and wedge-shaped or rounded at the 

 base, finely or on vigorous shoots coarsely serrate, thin and firm, bright yellow-green 

 above, glabrous or rarely puberulous and paler below, 2'-3' long, ^'-1' wide, or on 

 vigorous shoots occasionally 6'-7' long, and 1^' wide, with stout yellow midribs 

 and numerous slender oblique primary veins arcuate and often united near the 



slightly thickened revolute margins; their petioles slender, somewhat flattened on 

 the upper side, and in falling leaving small nearly oval obcordate scars. Flo-wers: 

 aments densely flowered, glabrous, short-stalked, l|'-2i' long, the pistillate becoming 

 2\'-A' long before the fruit ripens, their scales broadly obovate, glabrous, thin, sca- 

 rious, light brown, deeply and irregularly cut into numerous dark red-brown fili- 

 form lobes; disk of the staminate flower cup-shaped, slightly oblique, short-stalked; 

 stamens 12-20, with short filaments and large light red anthers; disk of the pistil- 

 late flower shallow, cup-shaped, slightly and irregularly lobed, short-stalked; ovary 

 ovate, more or less 2-lobed, with a short or elongated style and 2 oblique dilated 

 irregularly lobed stigmas. Fruit broadly ovate, often rather abruptly contracted 

 above the middle, short-pointed, thin- walled, 2-valved, on stems often \' long; seeds 

 ovate or obovate, rather obtuse, light brown, nearly \' long. 



A tree, 50-60 high, with a trunk rarely more than 18' in diameter, slender 

 erect branches forming a narrow and usually pyramidal head, and slender glabrous 

 or rarely puberulous branchlets marked by pale lenticels, at first light yellow- 

 green, becoming "bright or dark orange-colored during their first winter, pale yellow 



