Fruits with sepals 12-15 mm long . Sepals broadly winged . Above ground parts die during the cold season, but the red-brown, often arched, grooved, hollow stems with zigzag twigs can persist through winter. Sometimes a few fruits cling to twigs. Disturbed moist sites, roadsides, riparian and wetland areas.
Plants typically grow in open, sunny areas on moist soils in cool temperate climates.
Grows on a wide range of soil types. Tolerates some soil dryness. Rhizome fragments disperse with water currents or flooding and with natural or human facilitated soil movement. Plants produce abundant seed, but a large proportion is non-viable when fertile male plants are rare. Seedling survival is usually low, but plants are persistent once established.