General: Perennial grass from rhizomes; stems smooth, (30) 60-150 (200) cm tall.
Leaves: Sheaths rough, the hairs angled backwards; blades (2) 6-10 mm wide, 2-6 (20) cm long, flat, strongly roughened on the margins with the hairs angled backwards, abruptly narrowed just below the base, the 2 margins freed from the sheaths at about the same level; ligules smooth, minutely jagged, more or less fringed with fine hairs, blunt, about 1 mm long.
Flowers: Inflorescence a panicle, 10-20 cm long, with reduced, axillary panicles in the upper sheaths that often bear spikelets that are small, closed, infertile; glumes lacking; lemmas about 5 mm long, bristly-hairy, unawned; paleas equalling the lemmas; anthers 1-1.5 mm long; lodicules 0.3-0.4 mm long.
Swamps, lakeshores and wet ditches in the lowland and steppe zones; rare in SC BC (Osoyoos and Ellison Lakes) and SW BC (lower Fraser Valley); circumpolar, E to NB and S to ME, MA, PA, NC, FL, MS, LA, TX, NM, AZ and CA; Eurasia, S America.
