74 SALICACEAE. 



araents on leaf y branchlets ; staminate dense, 3-5 cm. long; scales pale, oblong, 

 more or less dentate; stamens 5 or more, the filaments hairy at the base; 

 pistillate rather loose, the pale oblong scales hairy at the base, deciduous; 

 carpel glabrous, short-pedicelled ; stigma nearly sessile. Common on stream 

 banks. 



Salix macrostachya Nutt. Shrub, 2-3 m. high; leaves narrowly lanceolate, 

 acuminate, nearly sessile, entire, 5-8 cm. long, densely sericeous on each side; 

 stipules very small; staminate aments 2-5 cm. long, the scales ovate, acute, 

 woolly. On overflowed bars near Wawawai where only the staminate plants 

 have been found. 



Salix argophylla Nutt. Differs from 5. exigua only in its more or less 

 pubescent capsules. Intergrades are numerous. Common along streams. 



Salix exigua Nutt. Shrub 3-5 m. tall, usually with a single trunk; bark 

 rough, longitudinally cracked; twigs glabrous; leaves acute, subentire, dentic- 

 ulate, narrowly lanceolate or oblanceolate, 3-10 cm. long, 4-10 mm. wide, 

 glabrate above, sparsely appressed-silky beneath, the veins obscure; petioles 

 very short; stipules none or very small; aments on leafy branchlets, solitary 

 or 2-4; staminate aments 2-5 cm. long, slender, the scales lanceolate, acute; 

 capsules glabrous, sessile; stigmas sessile. Common along streams. 



Salix melanopsis Nutt. Much like 5. exigua; twigs glabrous; leaves 

 glabrous on both sides or glaucous beneath, remotely denticulate; stipules 

 triangular-ovate, acute, few-toothed; capsules glabrous; stigmas sessile; 

 scales obtuse. Low shrub on the edge of Snake River, where it is frequently 

 covered with water until July; also on the banks of the Spokane River. 



Salix piperi Bebb. Large shrub, 5-6 m. tall; leaves petioled, oblong or 

 oblanceolate, obliquely acute or acuminate, serrulate, shining green above, 

 densely glaucous and somewhat pubescent beneath; stipules rare, if present, 

 triangular; aments appearing with the leaves; staminate cylindrical, 3-5 cm. 

 long, short-peduncled; scales black, hairy; stamens 2, the glabrous filaments 

 united at the base for half their length; pistillate aments small, 1-3 cm. long, 

 on short leafy peduncles; capsules glabrous, short-pedicelled; style about 

 equalling the stigma. Along streams, infrequent. 



Salix cordata Muhl. Heart-leaved Willow. Shrub, 2-5 m. tall, with elon- 

 gate branches; leaves oblong or oblong-lanceolate, acuminate, glandular- 

 serrulate, rounded or cordate at the base, nearly glabrous above, glaucous 

 beneath, 4—8 cm. long; petioles stout; stipules conspicuous, reniform; aments 

 appearing with the leaves, on leafy peduncles; staminate narrow, dense- 

 flowered, 4-6 cm. long, the black hairy scales persistent; pistillate looser; 

 capsules glabrous, the long pedicels far exceeding the scales; style as long as 

 the stigmas. Common along streams. Our form is somewhat different from 

 the typical plant as found in the Atlantic States. 



Salix pyrifolia Anders. Shrub, 1-3 m. high, with slender shiny brown 

 twigs; leaves thin, ovate-lanceolate to obovate-oval, shortly acuminate, 

 rounded or subcordate at base, glandular serrulate, green on both sides, 3-7 

 cm. long; stipules lunate to broadly ovate; peduncles short, leafy; aments 

 appearing with the leaves, the staminate slender, 4-6 cm. long; filaments partly 

 united; pistillate aments 3-6 cm. long; capsules glabrous, 3-4.5 mm. long. 

 Along stream banks. This species has been much confused with 5. cordata. 



Salix bebbiana Sargent. Much branched shrub, 2-5 m. tall; leaves oblong, 

 elliptic, acute or acuminate, crenulate or nearly entire, pale and downy 

 beneath, green and puberulent above, strongly reticulate, 3-8 cm. long; 

 petioles short; stipules ear-shaped, usually falling quickly; aments on short 

 bracteate peduncles appearing with the leaves; staminate dense, the obtuse 



