SALICACEAE (WILLOW FAMILY) 131 



Leaves linear, acuminate; pistillate aments 1-2 cm. wide.' 

 Leaves canescent, entire or remotely denticulate; capsules mostly 5 



mm. long; pedicels 0.5-0.7 mm. long 6. S. exigua. 



Leaves bright green, denticulate; capsules mostly 6-7 mm. long; 



..pedicels 0.5-1 .5 mm. long . . . >.. . . , .7. S. fluviatjlis. 

 Leaves elliptical-oblanceolate, rather cloiaely denticulate; pistillate 



aments 7-^ mm. wide . . 8. S. melanopsis. 



6. Salix ezigua Nutt. Sylva 1: 75. 1842. Color effect grayish: leaves 

 lineaty .acute at both ends or acuminate at the apex, 5-12 cm. long, 2-10 mm. 

 wide, entire or remotely denticulate, opaque, more or less canescent on both 

 surfaces or silky with a fine silvery tomentum beneath,, or on both surfaces 

 on young shoots (then frequently mistaken for S.argqphylld) ; petioles 2-7 mm. 

 long: pedumeles sometimes 7 cm: long; staminate amenta 2-4 cm. long, about 

 7 mm. wide; the pistillate 3-6 cm. long, 1-1.3 cm. wide; scales lanceolate in 

 the pistillate aments, broader in the staminate, mostly acute, nearly glabrous 

 or white pilose on the margins, occasionally on the back' also: capsules nar- 

 rowly lanceolate, 4-6 (mostly 5) cm. long, sessile or on pedicels 0.5-0,7 mm. 



-long, especially at the base of the amentj glabrous or thinly villoiife; gland 

 about'0.5 mm. long; stigmas divided. (S. stenophylla Rydb. Bull. Torr.. Bot. 

 Club 28: 271. 1901, an inconstant, form; S. hiteosericea Rydb. Brit. Man. 

 316. 1901.) — Very commpn along rnountain streams and in wet places through- 

 out our range and westward; variable in foliage characters and sometjxnes very 

 difficult to distinguish from the next. 



7. Salix fluviatiUs Nutt. 1. c. 73. Color effect bright green or sUghtly 

 grayish: leaves liiiear or liiiear-Ia'nceolate, acute or acuminate at the apex, 

 acute at the base, S-12 cm. long, 2-15 mm. wide, remotely denticulate to 

 spinulose-denticulate; pure green and veiny on both sides, glabrous when 

 mature, often thinly villous with' long white hairs when young; petioles 2-9 

 mm. long: amehts'and'scales as iiithe preceding but the' pistijlate 1.2-3 cm. 

 wide (sometimes 10 cm. long in'lp'w humid regions); scales more nearly, 

 glabrous: capsules 5-8 (mostly 7) mm. long, longer east df our limits, glabrous, 

 or silky with long white hairs, especially when young, pedicellate; pedicels 

 0.5-1.5 mm. long; gland often 1 mm.' long. S.'longifolia'. Sandbar Willow. 

 {S. interior Rowlee, Bull. Torr. Bot. Club 27:' 253. 1900; S. lineanfolia Rydb. 

 1. c.) — Most common in' cistern Colorado and Wyoming, and in Montana and 

 Idaho, but not abundaii^t anywhere in our limits: exceedingly abundant east- 

 ward across the continent. . 



,8. Salix melanopsis Nutt. 1. c. 78. A tall, dark green shrub or small tree, 

 3-5 m. high, more divaricately branched than the' related species; twigs 

 brown or blockish, often lustrbii^:' leaves oblanceolate or elliptical, acute hi 

 both ends, 4-7 or 8' cni^ long, 6-15 mm. wide, rather closely denticulate, often 

 spinulbse'-denticulate, especially near the apex, or subentire, the margin 

 somewhat revolute in drying, dark green 'a.nd glabrous above, paler, strongly 

 veined, and usually thinly silky-villous beneath; stipules lanceolate to semi- 

 cordate, dentate^ aments slender, 3^ cm. long, the staminate 5-^ mm. wide, 

 the pistillate 7-8 mm. wide; scales oblong to obovate, sometimes erose at the 

 apiex, thinly pilose, the pistillate often plainly striate with 3-5 nerves: cap- 

 sules ovate-lanceolate, glabfous,' sessile or subsessile, 4-5 mm. long. Dusky 

 WiLLqw. — TjTJe locahty, old. Fort Hall near Pocartello, Idaho. Common in 

 northeastern Oregon, eastern' Washington, and British Columbia^ as far east as 

 the Selkirks. 



IV, Retusae. — Low, ^pressed, or creeping, Spepiee, less' than 1 dm. high: lea/ves 

 imirtvte, entire, glabrous: aments 2-4-jlowered: capsules glabrous; stigmas 

 sessile. A single, species within, our limits: , 



9. Salix Dodgeana Rydb. Bull. N. Y. Bot. Gard. 1: 277. 1899. Delicate, 

 suffruticose,'.? cm. high or less, frbfai short, "sleiideir, subterranean stemS; twigs 

 yellowish-rgreen, very. leafy: leaves ''dblbng or oval, 4-^5 'mm. long, acutish oi' 

 obtus?, light, green^, strongly veined: staminate ameilt generally 3-4-'fldwered; 

 stamens 2; filaments glabrous; pistillate aments geiierally 2-floWere'd; scales 

 oblong, truncate, sparingly villous-ciliate: capsule oblolig-ovoid, glabrous; Stig- 



