SALICACEAE. 75 



scales pale, hairy; stamens 2; filaments glabrous; pistillate looser, the linear 

 scales pale and pink-tipped; capsules pubescent, long-beaked, with sessile 

 stigmas, the slender pedicel equalling or exceeding the persistent scales. 

 Common along streams. 



Salix sitchensis Sanson. Shrub with smooth gray bark, 2-7 m. high; 

 branchlets slender, at first downy; leaves oblong or somewhat obovate, mostly 

 acute, dark green above, the veins conspicuous, covered beneath with an ap- 

 pressed satiny white pubescence, entire or obscurely crenate, 5-10 cm. long; 

 petioles short; aments long, slender, ascending, densely flowered, 2-8 cm. long; 

 scales dark, villous; capsules ovate-conical, acute; style elongate; stigmas thick, 

 erect. About Spokane and in the Blue Mountains. 



Salix bella Piper. Pretty Willow. Shrub, 2-4 m. tall, with slender erect 

 branches, the bark gray and smooth; branchlets shining yellow, usually 

 glabrous, very brittle; leaves lanceolate or oblong, or oblong-obovate, acute, 

 3-6 cm. or more long, green and glabrate above; densely silvery- woolly beneath, 

 entire or nearly so; petioles short; stipules lunate, usually present; aments 

 appearing before the leaves; stamina te sessile, short and thick, 1-2 cm. long; 

 scales acute, black, densely villous; stamens 2; pistillate short-peduncled, 

 2-3 cm. long; scales black, obtuse, densely villous; capsules silky hairy, 

 nearly sessile; style 1.5 mm. long. Along streams especially near the moun- 

 tains. 



Salix scouleriana Barratt. Shrub or tree, 4-10 m. tall, with dull gray bark; 

 leaves very variable, oblong, elliptic or obovate, acute, acuminate or obtuse, 

 entire or serrulate, green above, usually downy beneath, this becoming rusty 

 in age, 2-12 cm. long; petioles rather short; stipules large, ear-shaped, dentate, 

 persistent on sterile shoots; aments appearing before the leaves, very densely 

 flowered; scales black, hairy, persistent; staminate aments sessile; stamens 2, 

 with glabrous separate filaments; pistillate short-peduncled; carpels hairy, 

 long-beaked, the pedicels equalling the scales; stigmas sessile. Frequent 

 along streams and in open coniferous woods. 



104. POPULUS. 



Trees with scaly resinous buds and rounded or angled twigs; 

 leaves long-petioled, broad or narrow; bracts of the aments 

 fimbriate or incised; disk cup-shaped, oblique, lobed or entire; 

 staminate aments dense, pendulous; pistillate aments sometimes 

 raceme-like by the elongation of the pedicels, pendulous, erect 

 or spreading; staminate flowers with 4-60 stamens; filaments 

 distinct; ovary sessile; tuft of hair on the seed very conspicuous. 



Bark smooth; petioles flattened; capsules oblong-conic, 



smooth. P. tremidoides. 



Bark rough; petioles terete; capsule globose, hairy. 



Leaves broadly ovate, truncate at base; capsules globose, 



pubescent. P. trichocarpa. 



Leaves lanceolate or oblong-lanceolate, obtuse or acute at 



base; capsules ovoid, smooth. P. angustifolia. 



Populus tremuloides Michx. Aspen. Small tree, 10-12 m. tall, with 

 smooth light bark; leaves broadly ovate, subcordate or obtuse at base, abruptly 

 acuminate, 3-8 cm. long, ciliate when young, glabrate; petioles long and slender, 

 much flattened laterally; staminate aments dense, 3-5 cm. long; stamens 7-10; 

 bracts long-ciliate; pistillate aments 5-10 cm. long. Common on north hill- 

 sides and along streams. 



