Salix spp.
Family: Salicaceae
Salix image
Liz Makings  
PLANTS: Shrubs or trees, not clonal or clonal by root suckers. WINTER BUDS: with one external budscale; budscale margins coalescent or free and overlapping. STEMS: erect or spreading, pendulous in some naturalized trees, flexible or brittle at base, not, or thickly, glaucous. LEAVES: stipules leaf-like, rudimentary or absent, usually not strongly glandular; petioles lacking glandular dots near base of blade, dotted or lobed; proximal leaves on vegetative shoots or leaves on flowering branchlets entire, gland-dotted or toothed; mature blades linear to broadly obovate, the margins entire to toothed, the surfaces hairy, glabrous or becoming so, the hairs white or white and rust-colored. INFLORESCENCE: cylindrical or subspherical catkins, sessile or on short leafy branchlets, emerging before (precocious), with (coetaneous), or after (serotinous) the leaves. FLOWERS: subtended by a bract; pistillate floral bracts persistent after flowering or deciduous; stamens (1-) 2(-8); pistils sessile or stipitate, subtended by 1 to several flattened, rod-like, square or cupulate nectaries. FRUIT: lanceolate or ovate. x = 19, 22. NOTES: Ca. 450 spp. worldwide, especially n temp., arctic. (Ancient name for willow). Argus, G. W. 1986. Syst. Bot. Monog. 9:1-170. Argus, G. W. and C.-E. Granfelt. 1988. Madrofio 35:5. Argus, G.W. & C.L. McJannet. 1992. Brittonia 44: 461-474; Dom, R.D. 1976. Canad. J. Bot. 54: 2769-2789; Dom, R.D. 1977. Rhodora 79: 390-429. Taxonomically difficult and often highly variable. Not all specimens will key easily; sprout shoots and other extreme variants are not included in keys. REFERENCES: Argus, George W. 1995. SalicaceaePart 2. Salix. J. Ariz. - Nev. Acad. Sci. 29(1): 39
Catkins mostly ascending or spreading, seldom drooping, developing before, with, or less often after the lvs, their scales mostly entire, sometimes erose or shallowly toothed at the tip; fls with a single short and broad to slender and elongate ventral protuberance called a gland, or the staminate fls of some spp. also with a dorsal gland; stamens typically 2, seldom only 1 (by fusion of 2), or in some spp. 3-8; stigmas 2, entire or more often bifid; capsules 2-valved; shrubs or less often trees, sometimes depressed and mat-forming; winter-buds covered by a single nonresinous scale. 300+, mainly N. Temp. Taxonomy complicated by hybridization.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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