S. purpùrea, L. (Purple W.) Leaves oblanceolate or tongue shaped, slightly serrulate, very smooth, glaucescent, subopposite; stipules obsolete; aments densely flowered, narrow-cylindrical, the sterile at least closely sessile, with only very small bracts at base; scale small, round, crisp-villous, tipped with dark purple; capsules grayish-tomentose, ovate-conical, obtuse.—Low grounds; commonly cultivated for basket-rods. (Adv. from Eu.)
[*][*] Capsules glabrous.
[+] Tall shrubs, 4–10° high; leaves lanceolate or ovate-lanceolate, 2–4´ long, acute or acuminate (on vigorous shoots rounded, truncate or cordate at base), serrate; sterile aments very silky, with a few bracts at base, 1´ long or more, the fertile leafy-peduncled, in fruit 2´ long or more; capsules tapering, pointed.
[++] Leaves soon smooth; capsules long-pedicelled; style medium.
14. S. cordàta, Muhl. (Heart-leaved W.) Leaves oblong-lanceolate or narrower, on the flowering branches often tapering at base, sharply serrate, finely denticulate or subentire, green both sides or scarcely paler beneath, the young often silky or downy, especially on the midrib, not turning black in drying; stipules reniform or ovate, serrate, usually large and conspicuous; aments rather slender; capsules greenish or refuscent, 2–3´´ long. (S. rigida, Muhl.)—Var. angustàta, Anders. Leaves narrower, gradually acuminate, finely serrate.—In wet places and along streams, etc.; our most widely distributed and variable species.—S. myricoìdes, Muhl. (S. cordata, var. myricoides, Darl., Fl. Cestr., 3 ed.), is a hybrid between this species and S. sericea, having the leaves, even those of the most vigorous shoots, tapering and rather acute at base, glaucous or glaucescent beneath and sparsely appressed-hairy; stipules small, ovate, pointed; capsules more or less silky when young, becoming glabrate, shortly pedicelled; twigs brittle at base. A hybrid with the European S. incana (surprising on account of the rarity of the cultivated parent) is found at Ithaca, N. Y. (Dudley).
15. S. glaucophýlla, Bebb. Leaves varying from ovate with a broadly rounded base to oblong-lanceolate and equally pointed at both ends (3–4´ long, nearly 2´ wide), glandular-serrate, subcoriaceous, glabrous throughout, dark green and shining above, glaucous beneath, the young drying black; stipules large, ear-shaped, dentate; aments thick, oblong-cylindrical, in size and silkiness resembling n. 6; capsules attenuate-rostrate, 3–5´ long, greenish, drying brown.—Var. angustifòlia, Bebb; leaves narrower (3´ long, ¾´ wide), pointed at both ends. (S. angustata, of ed. 2, in part.)—Var. brevifòlia, Bebb; leaves obovate, about 1´ long, strongly veined.—Common on the sand dunes of Lake Michigan, and occasionally found away from the lake shore in N. Ill. and Wisc.
16. S. balsamífera, Barratt. Leaves broadly rounded and usually subcordate at base, at first very thin, subpellucid and of a rich reddish color, at length rigid, dark green above, paler or glaucous and prominently reticulate-veined beneath, slightly glandular-serrulate; petioles long and slender; stipules obsolete; fertile aments becoming very lax in fruit, the long slender pedicels 6–8 times the length of the gland; style short. (S. pyrifolia, Anders.)—In open swamps along our northern boundary, Maine to Minn., and northward; White Mountains of N. H. (Little, 1823; rediscovered by Pringle, and C. E. and E. Faxon). A much branched shrub, growing in clumps; recent twigs shining-chestnut on the sunny side.
[++][++] Leaves clothed, even when fully grown, with a long silky tomentum on both sides, which is finally deciduous; capsule subsessile; style elongated.
17. S. adenophýlla, Hook. Leaves ovate or very broadly lanceolate, cuspidate-acuminate (1–2´ long), dull green both sides, very closely serrate with fine projecting gland-tipped teeth; stipules conspicuous, ovate-cordate, glandular-serrate, exceeding the short stout petioles, which are dilated at base and embrace the obtuse silky buds; aments leafy-peduncled, the fertile not rarely becoming 4´ long, densely flowered.—Shores of the Great Lakes, rooting extensively in the sand-dunes. A large straggling shrub, with stout tomentose twigs and crowded leaves. Hybridizes with S. cordata.
[+][+] Low erect shrub, 1–3° high; leaves small, entire; capsules oblong-cylindric; stigmas sessile or nearly so.