314 FLORA. 



Salix alba coerulea (J. E. Smith) Koch. Mature leaves bluish green, glabrous, glau- 

 cous beneath. Occasional in the Eastern States. 



Salix alba vitelllna (L.) Koch. Mature leaves glabrous above ; twigs yellowish green. 

 The commonest form in North America. 



7. Salix Babylonica L. Weeping Willow. Ring Willow. (I. F. f. 

 1 1 79.) A large tree, with rough gray bark, sometimes attaining a height of 20 m. 

 and a trunk diameter of 18 dm., the twigs slender, green, elongated, drooping, 

 leaves serrulate all around, narrowed at the base, sparsely pubescent when young, 

 glabrous when mature, green above, paler beneath, 10-18 cm. long, 6-12 mm. wide, 

 sometimes curling into rings; petioles 6-12 mm. long, glandular above; aments 

 appearing on short lateral leafy branches; bracts ovate- lanceolate; style almost 

 none; capsule ovoid-conic. Widely cultivated and sometimes spreading by the dis- 

 tribution of its twigs. Native of Asia. April-May. 



8. Salix balsamifera (Hook.) Barratt. Balsam Willow. (I. F. f. 1201.) 

 A shrub, 12-30 dm. high, the twigs glabrous, shining, the youngest foliage pubes- 

 cent. Mature leaves elliptic, ovate-oval or obovate, thin, glabrous, acute or some 

 of them obtuse at the apex, rounded or subcordate at the base, dark green above, 

 glaucous and prominently reticulate-veined beneath, 5-8 cm. long, 2-4 cm. wide, 

 slightly crenulate-serrulate, the minute teeth glandular; stipules minute or none; 

 petioles slender, 6- 1 2 mm. long; aments expanding with the leaves, leafy-bracted 

 at the base, cylindric, the staminate dense, about 2 cm. long, the pistillate rather 

 loose, 5-7 cm. long in fruit; bracts villous, persistent; style very short; capsules 

 very narrow, acute, 4-5 mm. long. In swamps, Lab. to Man., south to Me. and 

 Minn. May. 



9. Salix glaucoph^lla Bebb. Broad-leaved Willow. (I. F. f. 1199.) A 

 shrub, 1-3 m. high; foliage glabrous or when young sparingly pubescent. Mature 

 leaves ovate, obovate or oblong-lanceolate, white-glaucous beneath, short-acuminate, 

 the base rounded or acute, serrulate with gland-tipped teeth, 5-10 cm. long, 1-3 cm. 

 wide; stipules large, persistent; petioles stout, 6-12 mm. long; aments expanding 

 before the leaves, leafy-bracted at the base, the staminate 3-5 cm. long, the pistil- 

 late 4-7 cm. long in fruit; bracts densely white- villous, persistent; style filiform; 

 capsule beaked from an ovoid base, acute. On sand dunes, Lake Michigan, N. 111. 

 and Wis. April. 



10. Salix Mackenziana Barratt. Mackenzie's Willow. A small tree, with 

 smooth pale yellowish or grayish bark. Young branches glabrous or slightly 

 puberulent, yellow or often tinged with bright red; mature leaves oblanceolate or 

 lanceolate, cuneate at the base, finely crenulate-serrate or entire; stipules large, 

 oblique, reniform and somewhat persistent; aments on short leafy-bracted branches, 

 the pistillate 4-6 cm. long in fruit; style very short; capsule ovoid, acute, 6-8 mm. 

 long. In damp soil from Man. to N. W. Terr, and N. Cal. April. 



11. Salix cordata Muhl. Heart-leaved Willow. (I. F. f. 1198.) A 

 shrub, 15-35 dm. high, the twigs puberulent or glabrous; young leaves pubescent,, 

 mature leaves oblong-lanceolate, green on both sides or paler beneath, acuminate at 

 the apex, narrowed, obtuse or subcordate at the base, sharply serrulate with glan- 

 dular teeth; stipules oblique, serrulate, usually large and persistent; petioles 8-18 

 mm. long; aments bracted at the base, expanding before the leaves, the staminate 

 about 2 cm. long, the pistillate 4-6 cm. in fruit; style short; capsules narrowly 

 ovoid, acute. In wet soil, N. B. to Br. Col., south to Va., Mo., Colo, and Cal. Hy- 

 bridizes with S. sericea and other species. April- May. 



Salix cordata angustata (Pursh) Anders. Leaves narrower, linear-lanceolate. Range 

 of the type. 



Salix cordata rfgida (Muhl.) Carey. Leaves broad, sharper serrate especially at the 

 cordate base, strongly veined ; pedicels little if at all longer than the bracts ; stigmas sub- 

 sessile. N. B. to Penn. 



12. Salix Missouriensis Bebb. Missouri Willow. (I. F. f. 1200.) A 

 tree, often 15 m. high, the trunk sometimes 4.5 dm. in diameter, the thin gray 

 bark with small appressed scales. Twigs of the season pubescent or puberulent; 

 leaves lanceolate, or oblanceolate, acuminate, finely serrate with minute gland- 

 tipped teeth, rounded or narrowed at the base, pubescent when young, glabrous or 

 nearly so when mature, green above, pale and usually glaucous beneath, 7-15 cm. 



