General:
Perennial, somewhat tufted herb from short rhizomes; stems 15-70 cm tall, usually longer than the leaves.

Leaves:
Sheaths tight; blades numerous, borne on the lower part of the stem, 1-2.5 mm wide, flat, the lowermost leaves often reduced.

Flowers:
Spikes 4 to 9 in a 3- to 5-cm long, narrow, interrupted inflorescence, occasionally with a few of the uppermost spikes aggregated into a small cluster, egg-shaped, many-flowered, 4-7 mm long, ascending, with both female and male flowers, the female flowers towards the tips, the male flowers inconspicuous; lowermost bract reduced or rarely awnlike, about 0.5 cm long.

Fruits:
Perigynia egg-shaped, 2-3.5 mm long, 0.5-0.8 mm wide, dark green or brownish, minutely whitish-dotted, plano-convex, smooth, lightly nerved on both surfaces, unstalked, the beaks about 0.5 mm long, smooth, cleft on the upper surface; female scales egg-shaped, covering about 2/3 of the perigynia, pointed, green, with green midribs; stigmas 2; achenes lens-shaped, 1.2-1.7 mm long, filling the perigynia.

Notes:
This is a variable species whose taxonomy and distribution have not been sufficiently studied. Kalela (1965) distinguished the following three subspecies in British Columbia:

1. Plants densely tufted; stems 15-40 cm long, stiff with short stiff leaves; perigynia 2-2.5 mm long, with a dark brown tinge, the margins without wings, with thick walls, coarsely dotted/pitted....................... ssp. alaskana Kalela

1. Plants loosely tufted, stems 30-70 cm long, lax with long, lax leaves; perigynia 2-3.5 mm long, with a purplish or rusty tinge, with winged margins, thin-walled, finely dotted/pitted.

2. Spikes all separated; perigynia without sharp lateral margins and with faint nerves, light olive-green when ripe; achenes entirely filling the perigynia......................... ssp. sphaerostachya (Tuckerm.) Kalela

2. Spikes forming a terminal head, only the lowermost spike remote; perigynia with weak margins and nerves, olive-brown, with rusty-brown spots when ripe; achenes not entirely filling the perigynia.......................ssp. pacifica Kalela

Source:  The Illustrated Flora of British Columbia