Polygonum virginianum is a perennial herb to 1 m tall, colonial from thick, knotty rhizomes, erect, sheaths at nodes cylindrical, papery, hairy, margin bristle-fringed.
Leaves alternate, egg-shaped, to 15 cm long, 8 cm wide, dark green above, often with dark marking, pale below, often finely hairy, rough hairy above, tip tapered.
Flowers white or greenish, about 0.2 cm long, petals 4, flowers in clusters of 1-3 at nodes, distant from one another near base, more crowded above; inflorescence long, thin, to 50 cm terminal, blooming and fruiting July-Oct.
Fruit an achene ca 0.4 cm long, dispersed by action of hardened, spring-like styles when disturbed.
Wetland status: FAC.
Frequency in NYC: Frequent.
Habitat: Moist, open woods, swamp forests. Shade and drought tolerant. Frequent in disturbed urban woodlands along with Eupatorium rugosum (Ageratina altissima) and Aster divaricatus (Eurybia divaricata), (M. Gargiullo personal observation).