Cornus alternifolia is a shrub or small tree to 6 m tall; roots associated with VA mycorrhizae (Brundrett and Kendrick 1988); branches often in horizontal layers, twigs greenish to dark red-purple, glossy, lenticels gray, about 0.1 cm, pith white, leaf scars about 0.1 cm wide, more-or-less triangular, vein scars 3 (use lens), winter buds about 0.3-0.5 cm long, dark, major scales two, about equal, plus one or two smaller scales.
Leaves alternate, crowded at ends of twigs, stalk (petiole) long, blade 5-10 cm long, 3-6 cm wide, (Brand 2001), egg-shaped to widest above middle, tip long-pointed (acuminate), veins 5-6 pairs, up-curved, often parallel to leaf edge; autumn foliage yellow to red-purple (Brand 2001).
Flowers white, four-parted, radially symmetrical, petals 4, free, curved downward, calyx minute, stamens 4, alternating with petals and about as long, ovary inferior, stigma head-like (capitate), small, in dome- shaped to flat-topped clusters; blooms May-June.
Fruit fleshy, green to red becoming blue-black (Brand 2001), 1-seeded (a drupe), fruiting stalks bright red; fruiting Aug.-Sept.; eaten by birds, which disperse seeds.
Wetland status: UPL.
Frequency in NYC: Infrequent.
Habitat: Understory of moist woods. Prefers rich, moist soil pH 5.8-7.5 . Very tolerant of shade, index 8-10. Moderately tolerant of flooding and soil compaction. Intolerant of drought, salt (Hightshoe 1988; USDA, NRCS 2006). Twigs eaten by deer and rabbits (Martin et al. 1951).