The Flora of the Cayuga Lake Basin 167 



/. Leaves broader, (15) 18-50 mm. wide; serrations subcrenate, uneven, 

 1-4 per cm. ; stipules usually persistent. 

 g. Leaves glabrous beneath. 15. S. discolor 



g. Leaves with tawny, silky hairs beneath. 15a. S. d., var. latifolia 



d. Blade serrate almost or quite to the base. 



e. Leaves long-attenuate at apex, drooping ; twigs slender ; trees. 

 /. Leaves lanceolate with rounded base ; margins crenate-serrate ; teeth 



7-12 per cm. ; petioles slender, 10-30 mm. long. 2. S. amygdaloidcs 

 f. Leaves linear-lanceolate with acute or tapering base ; margins sharply 

 serrate ; teeth coarser, 4-8 per cm. ; petioles stouter, 3-10 mm. long. 



6. S. blanda 



r. Leaves acute or acuminate at apex, not long-attenuate, not drooping ; twigs 

 stouter. 

 /. Serrations coarse, 3-6 per cm., 0.4-1 mm. high ; leaves rather firm, 

 glabrous or nearly so; twigs fragile at base; trees. 



7. S. frag His 

 f. Serrations finer, 7-12 per cm., 0.1-0.4 mm. high; trees or shrubs. 



g. Leaves firm in texture, scarcely blackening in drying, tapering at 

 base ; trees. 

 h. Pubescence of blade rusty-shining; twigs erect and rather stiff. 



(S. alba, var. vitellitia 

 x S. hicida) 

 h. Pubescence of blade white or ashy ; twigs flexuous, and drooping 

 or curving. 

 i. Leaves distinctly silky above ; twigs greenish. 



8. S. alba 

 i. Leaves subglabrous above ; twigs yellowish. 



8a. S. a., var. z'itcllina 

 g. Leaves thinner, tending to blacken in drying, tapering or rounded at 

 base ; veins somewhat more prominent and less regular ; twigs rather 

 stiff, ascending. 

 h. Blade small, narrow, 4-10 (14) mm. wide; pubescence when pres- 

 ent tawny or rusty ; twigs generally fascicled toward ends of 

 branches. 13. 5". pctiolaris 



h. Blade usually larger and broader, (9) 10-30 mm. wide; twigs rarely 

 conspicuously fascicled. 

 i. Leaves more or less white-silky beneath. 14. S. sericea 

 i. Leaves not silky. 11. 5". cordafa 



1. S. nigra Marsh. Black Willow. 



Low alluvial stream banks and shores; common. May 20-June 15. 



Generally distributed ; especially abundant about the head of Cayuga Lake and in 

 the adjacent valleys. 



N. B. to N. Dak., southw. to Fla. and Tex., including the Coastal Plain. 



This species varies considerably in leaf outline, the form known as var. falcata 

 (Pursh) Torr. being a narrow extreme; a form with long petioles occurs occasionally. 



2. S. amygdaloides Anders. Peach-leaved Willow. 



In situations similar to the preceding, but often in drier soils ; common. May 5-25. 



Generally distributed throughout the basin ; abundant in the Inlet Valley and 

 around Cayuga Lake ; rare on the hills, as at Ringwood and Caroline, and in the 

 McLean region. 



Cent. N. Y. and Ont. to B. C. and the Rocky Mts., southwestw. to Tex. and N. Mex. 

 A tree primarily of the Central West, reaching its northeastern limit in this 

 region. 



A form with long, acuminate scales which sometimes equal or surpass the stamens is 

 occasional in the Inlet Valley. 



