132 SALICACEAE (WILLOW FAMILY) 



mas sessile, 2-cleft. Covering acres of ground on Electric Peak, Yellowstone 

 National Park, at 3,200 m. altitude; also on Sheep Mountain, Teton Forest 

 Reserve. 



V. CORDATAE. Shrubs 2-5 m. high; stems densely caespitose; twigs brown to 

 yellow, mostly slender, lustrous: leaves linear-lanceolate to ovate or broadly 

 oblanceolate, acute to long-acuminate, stipulate, glabrous; buds and slender 

 petioles yellowish: aments precocious or coetaneous, rather slender, subsessile 

 or on short, bracted peduncles; scales tawny to fuscous: capsules glabrous, 

 pedicellate; styles distinct. 



Leaves glaucous or at least distinctly pale beneath. 



Leaves linear-lanceolate; young branches with bluish bloom; 



capsules subsessile 10. S. irrorata. 



Leaves lanceolate or broader; branches without bloom; cap- 

 sules distinctly pedicellate. 

 Pedicels 1-2.3 mm. long. 



Leaves lanceolate, dark green above, mostly sharply 



serrate 11. S. cordata. 



Leaves broadly lanceolate or ovate-lanceolate, yellowish- 

 green, crenate-serrulate or subentire . . . 12. S. lutea. 

 Pedicels 3-4 mm. long; leaves oblanceolate or obovate . 13. S. Mackenziana. 

 Leaves deep rich green on both surfaces, never pale beneath. 



Leaves ovate or obovate, thin; pedicels 2.5-4 mm. long . 14. S. pyrifolia. 

 Leaves elliptic-lanceolate or oblong, thick; pedicels 1-2 mm. 



long 15.S. pseudomyrsinites. 



10. Salix irrorata Anders. 1. c. 117. Shrub 2-3 m. high; twigs dark brown 

 to yellowish, glabrous or downy-puberulent, often covered with a bluish 

 glaucous bloom, not shining: buds stout, broadly ovate, brown to yellow: 

 leaves linear-lanceolate or linear-oblanceolate, acute to acuminate at both 

 ends, 6-10 cm. long, 0.7-1.7 cm. wide, entire or undulate-serrulate, glabrous, 

 dark green and veiny above, with the whitish midrib prominent; glaucous 

 and finely reticulate beneath; stipules none: aments precocious, sessile, with- 

 out bracts; the staminate 1-2 cm. long; the pistillate 2-4.5 cm. long, 7-10 mm. 

 wide, densely-flowered: capsules ovate-conic, 3-4 mm. long, subsessile, gla- 

 brous; pedicels 0.5-1 mm. long; styles 0.5-0.7 mm. long; stigmas short, en- 

 tire or emarginate: scales small, fuscous, obtuse, clothed with long white 

 woolly hairs. Fairly common along streams and in wet places in the moun- 

 tains, at 1,200-2,500 m. elevation; southwestern Texas to southern Ari- 

 zona northward to northern Colorado. Shoots with large leaves resemble 

 S. lasiolepis very strongly. 



11. Salix cordata Muhl. Neue Schrift. Ges. Nat. Fr. Berlin 4: 236. 1803. 

 Shrub 2-5 m. high; twigs long, stoutish, brown or often yellowish, glabrous 

 to pubescent: leaves lanceolate or oblong-lanceolate or somewhat oblanceo- 

 late, acute to long-acuminate, usually narrowed at the base, 6-10 cm. long, 

 2-3 cm. wide, shallowly to deeply serrate, dark green above, glaucous and re- 

 ticulate beneath; stipules large, ovate to reniform, serrate: aments on short, 

 bracted peduncles; staminate 2-3 cm. long, 7-9 mm. wide; pistillate 2-3.5 cm. 

 long, 1-1.3 cm. wide; scales tawny, or fuscous at the tip, thinly pilose: cap- 

 sules 5-7 mm. long; styles 0.3-0.5 mm. long; pedicels 1-2 (mostly 1.5) mm. 

 long. Sparingly distributed throughout the Rocky Mountains and westward, 

 up to 2,000 m. 



lla. Salix cordata angustata (Ph.) Anders. Mon. Sal. 159. 1867. Leaves 

 narrower, about 1 cm. wide, acute or acuminate at both ends. Wet places 

 on the high plains and in the foothills east of the Rocky Mountains. 



116. Salix cordata Watsonii Bebb, Bot. Cal. 2: 86. 1879. Twigs often yel- 

 low, shorter and more divaricate: leaves smaller and more slender, subentire, 

 mostly dark green above, pale or subglaucous beneath : pedicels 1.5-2 mm. long. 

 [S. flava Rydb. Bull. Torr. Bot. Club 28: 273. 1901; S. Watsonii (Bebb) 

 Rydb. 1. c. 33: 157; S. Ormsbyensis v. Seem. Bull. Torr. Bot. Club 31: 403. 

 1904.] Rocky Mountains, westward to the coast. Intermediate in some re- 

 spects between S. cordata and S. lutea. 



12. Salix lutea Nutt. 1. c. 63. pi. 19. Shrub 2-5 m. high; twigs mostly 

 yellow,, reddish-brown on the sunny side, glabrous to puberulent: leaves 



