Amer. J. Sci. Arts 27: 239, fig. 65. 1835.
Plants loosely cespitose. Culms 10–35 cm, distally scabrous. Leaves 2–4 mm wide. Inflorescences: proximal bracts shorter than or exceeding inflorescences; spikes erect, separate, proximal spikes occasionally distant, pedunculate, short-oblong or cylindric, 5–20 × 2–3 mm; lateral 2–5 spikes pistillate, distalmost often reduced to 1–3 perigynia, of varying lengths, proximal 1 or more as long as the terminal spike; terminal spike pistillate, gynecandrous (proportion of pistillate to staminate flowers variable, as few as 2 or 3 perigynia at summit), or wholly staminate. Pistillate scales light to dark-brown, distal margins broadly hyaline, ovate, as long and as wide as perigynia, midvein lighter colored than body, conspicuous, often raised, prominent, distally scabrous, apex rounded, acute or mucronate. Perigynia ascending, greenish yellow or brown, veinless, elliptic, 2–2.5 × 1–1.5 mm, apex abruptly beaked, papillose; beak to 0.2 mm, truncate or obscurely bidentate, serrulate. Achenes nearly filling body of perigynia.
Phenology: Fruiting May–Aug.
Habitat: Alkaline meadows, lake margins, roadsides, ditches
Elevation: 200–2500 m
Alta., B.C., Man., Ont., Sask., Yukon, Alaska, Colo., Idaho, Mont., Nev., Utah, Wyo.