_Salix_ is the classical name of the Willow-tree.
CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES
Scales of the flowers deciduous, pale straw color. Stamens 3 or more. Leaves green on both surfaces; petioles without glands at the base of the leaves; branchlets easily separable. Branchlets reddish or grayish purple; leaves mostly narrow-lanceolate; capsule glabrous. 1. S. nigra (A, C, E). Branchlets yellowish-gray; leaves lanceolate to elliptic-lanceolate; capsule often more or less pubescent. 2. S. Gooddingii (F, G, H). Leaves (at least when fully grown) pale or glaucous below. Petioles without glands. Branchlets easily separable. Leaves narrow-lanceolate to lanceolate; petioles less than ½′ long. 3. S. Harbisonii (C). Leaves lanceolate to ovate-lanceolate, caudate; petioles ½′—¾′ long. 4. S. amygdaloides (A, B). Branchlets not easily separable. Capsules short-stalked (pedicels hardly more than 1/24′ long), ovoid-conic, up to ⅕′ in length; leaves more or less narrow-lanceolate, petioles glabrous or nearly so. 5. S. Bonplandiana (H). Capsules long-stalked (pedicels 1/12′—⅙′ long), more or less acuminate. Petioles puberulous; leaves lanceolate to ovate-lanceolate; stipules without glands on their inner surface; capsules hardly more than ¼′ long. 6. S. lævigata (G, F). Petioles hairy-tomentose; leaves lanceolate; stipules glandular on their inner surface; capsules ¼′—¾′ long. 7. S. longipes (C, D). Petioles glandular; leaves lanceolate to broadly ovate, caudate; branchlets easily separable. Leaves distinctly pale or glaucous below, lanceolate to ovate-lanceolate. 8. S. lasiandra (B, G). Leaves pale green below, ovate to elliptic-lanceolate, abruptly caudate-acuminate. 9. S. lucida (A). Stamens 2. Stigmas linear, 4 or 5 times longer than broad. Leaves linear, hardly more than ⅓′ long; anthers very small, globose; aments small, in fruit hardly up to ⅘′ in length. 10. S. taxifolia (H). Leaves linear-lanceolate to elliptic-lanceolate; up to 2′ in length; anthers ellipsoid; aments longer. 11. S. sessilifolia (B, G). Stigmas short, hardly 2 or 3 times longer than broad. Mature leaves covered below with appressed white silky hairs, those of flowering branchlets entire or barely denticulate. 12. S. exigua (B, F, G). Mature leaves glabrous below, those of flowering branchlets more or less distinctly denticulate. 13. S. longifolia (A, F). Scales of the flowers persistent, dark brown or fuscous, at least toward the apex (in _S. Bebbiana_ more or less straw-colored or tawny). Stamens 2. Ovaries glabrous. Leaves more or less denticulate or serrate; styles short. Base of leaf cuneate or rounded. Leaves acute, oblanceolate to narrowly lanceolate; filaments mostly united below. 14. S. lasiolepis (G). Leaves mostly acuminate; filaments free. Branchlets glabrous, lustrous; leaves oblanceolate to narrowly obovate, up to 2′ in length; pedicels ⅛′—⅙′ long; stipules small. 15. S. Mackenzieana (A, G). Branchlets pubescent; leaves narrowly lanceolate to ovate-lanceolate, 4′—6′ long; pedicels 1.5—2.5 mm. long. 16. S. missouriensis (A). Base of leaf mostly more or less cordate; leaves glabrous; filaments free; pedicels long. 17. S. pyrifolia (A). Leaves entire, oval to broad-obovate; branchlets villose-pubescent during their first season. 18. S. amplifolia. Ovaries pubescent (glabrous often in No. 23). Leaves covered with a soft dense felt-like tomentum, oblong-lanceolate to elliptic-lanceolate. 19. S. alaxensis (B). Leaves glabrous or more or less villose-pubescent below. Bracts of the flowers pale or tawny, often reddish at the tip; pedicels up to ⅕′ in length; leaves elliptic-lanceolate to obovate, reticulate beneath in age, pubescent or glabrate. 20. S. Bebbiana. Bracts of the flowers brown or fuscous. Stipules more or less distinctly developed; pedicels several times longer than the short styles. Leaves elliptic-lanceolate to oblong-elliptic; mostly glabrous in age. 21. S. discolor (A, B, F). Leaves oblanceolate to cuneate-obovate, covered beneath with short hairs or at maturity with a gray villose-pubescence. 22. S. Scouleriana (A, B). Stipules usually wanting; pedicels hardly longer than the distinct styles; leaves broad-elliptic to obovate-oblong, more or less grayish villose beneath. 23. S. Hookeriana (B, G). Stamens usually 1; leaves obovate-oblong, densely covered below with lustrous silvery white silky tomentum. 24. S. sitchensis (B, G).