Perennial, tufted herb from slender, creeping, branched rhizomes; stems (10) 20-50 cm tall, clustered, usually longer than the leaves, reddish-brown tinged at the bases.
Sheaths tight, breaking into threads at the bases; blades flat, channeled towards the base, 5 to 10 per stem, the margins somewhat turned in, borne on the lower 1/3 of the stem, 1-3 mm wide, the lower ones slightly reduced.
Spikes 2 to 4, the terminal one 1-2.5 cm long, the stalks 0.8-10 mm long, with many male flowers, the lower spikes 1 to 3, with female flowers, unstalked to short-stalked, erect; bracts subtending the lowest spike leaflike, sheathless or short-sheathing, shorter than the inflorescence, the others short, inconspicuous.
Perigynia broadly egg-shaped to nearly globe-shaped, 2.5-4.5 mm long, 2-2.3 mm wide, dull green to straw-coloured, convex, finely short-hairy, with 2 prominent marginal nerves, the bases short-stalked, the beaks 0.5-1.5 mm long, bidentate; female scales egg-shaped, rounded to tapered, slightly longer to somewhat shorter than the perigynia, straw-coloured to brownish, with lighter midribs, with translucent margins; stigmas 3; achenes 3-angled, with convex sides above, smooth, 1.8-2.5 mm long.
Two subspecies occur in BC :
1. Lower female spike elongate, short-stalked, its bract often short-sheathing; stalks of the male spike 4-10 mm long.................... ssp. inops
1. Lower female spike short, unstalked, its bract sheathless; stalks of the male spike 0.8-5 mm long.................... ssp. heliophila (Mack.) Crins
Source: The Illustrated Flora of British Columbia