Salix discolor is a shrub or small tree 2-5 m tall, usually multi-stemmed, branches low, bark gray, old bark irregularly fissured, twigs stout, young twigs hairy; winter buds to 1 cm, dark, covered by a single scale, somewhat flattened.
Leaves alternate, elliptic, 4-10 cm long, 2-5 cm wide, dark green above, mature leaves waxy-white or bluish-white below, toothed, mostly above middle, tip pointed, young leaves often reddish-hairy below, leaves expand early-mid May; winter plant leafless 167 days.
Flowers dioecious (sexes on separate plants), males silvery fuzzy about 3 cm long, showy, becoming yellowish and elongate; blooms Feb.-early April (Britton 1874).
Fruit a dry capsule, seeds small, hairy, wind dispersed, April-May.
Wetland status: FACW.
Frequency in NYC: Common.
Habitat: Open wetlands and shrublands, wet fill. Tolerates concrete debris, prefers soil pH 6.5-7.5. Tolerant of drought, flooding, salt, soil compaction. Very intolerant of shade, index 0-2 (Hightshoe 1988).
Notes: Twigs eaten by rabbits, buds eaten by squirrels (Martin et al. 1951). Leaves are eaten by the imported willow leaf beetle, Plagiodera versicolora, (Coleoptera, Chrysomelidae) a small, 0.5 cm long, oval, shiny black beetle. Adults overwinter in loose bark of trees and feed on leaves as they expand in spring. Yellow eggs are laid in patches on leaf undersides. The blackish larvae feed on leaf undersides, stripping the green tissue and skeletonizing leaves. Older larvae feed on upper leaf surface as well. These beetles may produce two generations in one growing season. The beetles are preyed upon by Schizonotus sieboldi (S. latus), a parasitic chalcidoid wasp that lays its eggs in beetle pupae. The beetles are also attacked by lady beetles, lacewings, predacious bugs and spiders (Johnson and Lyon 1991; Stokes 1983; Drooz 1985). The American dagger moth, Acronicta americana; also eats willow leaves (Tallamy 2003). Pussy willow may be infected by Cryptodiaporthe salicella (Deuteromycotina, Coelomycetes). This fungus causes cankers at wound sites, lenticels or nodes, that kill branches. It usually infects plants stressed by injuries, insects or other fungal infections (Agrios 1988; Johnson and Lyon 1991; Sinclair et al. 1987; Hightshoe 1988).