General: Perennial, loosely tufted herb from short rhizomes; stems often decumbent, 10-65 cm tall, often rooting at the nodes.
Leaves: Located on the lower part of the stem, nearly circular in cross-section, tapered, the early leaves stiff, with prominent complete cross-walls; sheaths open, with short, rounded, ear-shaped lobes.
Flowers: Inflorescence terminal, 7-15 cm long, open, the heads numerous, small, conic, mostly 6- to 12-flowered; perianth segments dark brown, (2) 2.5-3 mm long, pointed, the inner about equal to the outer; stamens 6; anthers shorter than the filaments.
Fruits: Capsules, tapered to the tips, slightly longer than the perianth segments; seeds barrel-like, about 0.4 mm long, lacking tail-like appendages.
Lakeshores, riverbanks and disturbed soil in the lowland, steppe and montane zones; common in BC south of 55degreeN; circumpolar, N to AK, disjunct E to ON, PQ and NF and S to ME, PA, NC, KY, IL, MN, NE, NM, AZ and CA; Eurasia.
