Plants not cespitose; rhizomes long. Culms erect, 5-31 cm. Leaves: sheaths and bases from previous year´s leaves persistent; blades widely V-shaped in cross section, to 21 cm × 3 mm. Scales ovate, 2.8 × 1.5 mm. Perigynia ovate, (1.5-)2-2.8(-3) × 1.5 mm, body tightly enveloping achene for entire length. Achenes 1.5-1.8 × 0.9-1.2 mm.

Fruiting Jun-Sep (depending on elevation). Dry ridge sites, fellfields with gravelly and noncalcareous soils; 3300-3900 m; B.C.; Calif., Colo., Idaho, Mont., Oreg., Utah, Wash., Wyo.

Compared to Carex scirpoidea subsp. pseudo-scirpoidea, C. scirpoidea subsp. scirpoidea occurs at relatively lower elevations and in wetter sites with calcar-eous soils.