Proceeding's of the Ohio State Academy of Science 125 



of basal brittle zones. The charcoal from the larger species used 

 for making gunpowder. 



1 . Twigs decidedly pendulous or "weeping", green or yellowish-green ; 

 leaves linear-lanceolate, acuminate, serrulate, smooth, rather pale 

 beneath, petioles glandular above ; capsule glabrous, pedicel very 

 short, stigma sessile. ^. babylonica. 



1 . Twigs not pendulous nor weeping, but some may be drooping. 2. 



2. Leaves tapering to the short petioled or nearly sessile base, linear- 



lanceolate, remotely denticulate, coarsely silky when young, usu- 

 ally glabrate in age ; shrubs or small trees with a narrow, slender 

 crown ; capsule glabrous or silky ; stamens 2. 5". Huviatilis. 



2. Petioles present and rather prominent and slender except in some 



individuals. 3. 



3. Leaves silky, tomentose, or hairy below when mature; stamens 2. 4. 



3. Leaves glabrous below, or nearly so, when mature, sometimes finely 



pubescent when young. 5. 



4. Leaves long linear-lanceolate, sparingly repand-crenulate, or entire, 



white or silvery silky beneath, without glands on the petiole, acu- 

 minate ; twigs terete, green ; capsule nearly sessile, silky or to- 

 mentose, style long. S. viminalis. 

 4. Leaves lanceolate, narrowed at the base, serrulate, silky pubescent 

 and glaucous beneath, usually with glands on the petiole at the 

 base of the blade ; capsule glabrous, pedicel very short, stigma 

 sessile. 6^. alba. 



4. Leaves ovate-lanceolate^ slender -pointed, firm, pubescent or white- 



tomentose beneath, sharply serrate or entire ; bracts yellow, linear- 

 oblong or lanceolate ; capsule silky or tomentose, pedicel filiform. 

 5. bebbiana. 



5. Petioles usually without glands, or if with glands then the leaves 



of the ovate type and short pointed ; stamens 2. 6. 



5. Petioles usually with glands on the top or at the base of the blade; 



stamens 8-12, in one species 2 ; capsule glabrous. 8. 

 G. Length of leaf-blade less than 3 times its breadth; mature leaves 

 thin and dull, elliptic, ovate-oval, or obovate, acute or obtuse at 

 the apex; stamens 2. S'. balsamifera. 



6. Length of leaf-blade 3 times its breadth or more. 7. 



7. Leaves oblanceolate or spatulate, acute, serrulate, somewhat glaucous 



beneath ; twigs purplish, flexible ; filaments of stamens imited ; 

 capsule silky or tomentose, sessile ; stigma sessile. 5". purpurea. 

 7. Leaves lanceolate or oblanceolate, acuminate, finely serrate with mi- 

 nute gland-tipped teeth, pale and glaucous beneath ; twigs of the 

 season pubescent or puberulent; capsule glabrous. 5". missouriensis. 



