Rhododendron periclymenoides is a shrub to 2 m tall, somewhat colonial by root sprouts, roots associated with highly specialized ascomycota ericoid mycorrhizae, (Allen1991); branched above, young branches tend to be in distinctive, umbrella-shaped pattern at ends of older stems, bark gray, twigs not hairy, winter bud scale hairless.
Leaves alternate, but often tightly spiraled at ends of twigs, oblong or widest above middle, to 10 cm long, not hairy except along margin and midrib below.
Flowers pink, showy, usually odorless, to 5 cm long, tubular, irregular (bilaterally symmetrical), hairy, blooms just before leaves appear, May.
Fruit dry, splitting open to disperse very small seeds, wind dispersed, autumn-winter.
Wetland status: FAC.
Frequency in NYC: Occasional; listed as exploitably vulnerable in NYS (USDA, NRCS 2010).
Habitat: Understories of moist upland, undisturbed, forests. Acid soil of moist oak forests, soil pH 4.3-5.5 (USDA, NRCS 2010). Tolerant of shade, soil compaction, flooding, saturated soil for up to 25% growing season Moderately tolerant of drought. Intolerant of salt (Hightshoe 1988).
Notes: Twigs eaten by deer and rabbits (Martin et al. 1951).