obtuse to acute, serrulate, glaucous; leaf blades linear-lanceolate to lanceolate, 

 7-15 cm. long, 1-3 cm. wide, long-acuminate, shallowy serrulate, acute to rounded 

 at base, dark green above, strongly glaucous beneath and often somewhat pubes- 

 cent; aments coetaneous, 3-1 1 cm. long; scales obovate to oblanceolate, yellowish, 

 villous, deciduous; stamens 4 to 8, the free filaments pubescent at base; capsules 

 narrowly ovoid-lanceolate, 3-3.5 mm. long, glabrous; styles and stigmas minute. 

 5. longipes Shuttlew., S. Wardii Bebb. 



Along rocky water courses, stream bottoms and in coastal sands, in Okla. 

 (Pushmataha Co.) and s.-cen. Tex., spring; W.I. and Fia., w. to Tex. and Okla., 

 n. to the Potomac Valley, the Ohio River in w. Pa. and s. Ind. 



10. Salix taxifolia Kunth. Yew-leaf willow. 



Shrub or tree 4-12 m. tall, with furrowed bark, the lower branchlets somewhat 

 drooping and the color effect in mass grayish-white; branchlets much-branched, 

 slender, yellowish-gray or somewhat brownish, at first densely white- or silvery- 

 pubescent, eventually grayish and glabrate; stipules mostly wanting; leaves short- 

 petiolate; blades linear to linear-oblanceolate, 1-5 cm. long, 2-5 mm. wide, 

 acutish at both ends, entire to remotely and minutely denticulate, densely silvery- 

 pubescent when young, becoming gray-pubescent or puberulent with age, more or 

 less densely crowded on the twigs; aments serotinous, 1-1.5 cm. long in fruit, 

 subglobose to ovate-oblong, usually several terminating densely-leaved seasonal 

 shoots; scales yellowish, obovate to ovate, deciduous; stamens 2, the free filaments 

 pubescent on the lower third or half; ovaries usually pubescent but sometimes 

 glabrate; capsules sessile, lanceolate, 4-5 (-8) mm. long, thinly pubescent to 

 glabrate; styles 0.1-0.2 mm. long; stigmas 0.4-0.7 mm. long, divided. 



Along streams, about springs and bodies of water, in w. Tex. (Brewster, Jeff 

 Davis and Presidio cos.), N. M. (Grant Co.) and Ariz. (Cochise, Santa Cruz and 

 Pima COS.), spring; also Mex. to Guat. 



Var. microphylla (Schlecht. & Cham.) Schneid. has very small leaves, Santa 

 Cruz Co., Ariz. 



11. Salix exigua Nutt. var. exigua. Gray sandbar willow. Fig. 388. 



Shrub 2—4 m. tall, gray-appearing; twigs pruinose to silky-tomentose; leaves 

 without stipules; blades tapering to a short petiole, 5-12 cm. long, linear to 

 linear-lanceolate, remotely denticulate, canescent to silky-pubescent on both sur- 

 faces, becoming glabrate with age; staminate aments on long peduncles, 2-4 cm. 

 long; stamens 2, the free filaments pubescent; pistillate aments 3-6 cm. long, on 

 leafy peduncles; scales lanceolate, acute, white-pilose; ovary glabrous or some- 

 times with 2 glands (var. nevadensis (Wats.) Schneid.); stigma sessile; capsule 

 subsessile to short-pediceled, 4.5-6.5 mm. long, ovoid-attenuate, glabrous to 

 sericeous and becoming glabrous. 



Along streams and near bodies of water, and swamps, usually at high elevations, 

 in the Edwards Plateau, Plains Country and Trans-Pecos of Tex., in N.M. (fre- 

 quent in mts.) and Ariz, (almost throughout the state), spring; from Calif, n. to 

 B.C. and e. to the w. Great Plains. 



11a. Salix exigua var. nevadensis (Wats.) Schneid. 



Differs (in part) from var. exigua in having browner and more glabrate branch- 

 lets, narrower glabrate and yellowish-green leaves, and somewhat more glabrate 

 flower scales. Along streams and near bodies of water, in canyons, from Calif., 

 Ida. and Ut., e. to s. Colo, and w. Tex. 



lib. Salix exigua var. stenophylla (Rydb.) Schneid. Silvery desert willow. 



Variety stenophylla differs from var. exigua in having narrower leaves and in 

 the much more dense silvery-pubescence of all vegetal parts, and branchlets and 



761 



