Plants cespitose; rhizomes never conspicuous. Culms erect, (30-) 35-65 cm. Leaves: sheaths and bases from previous year´s leaves persistent; ligules rounded; blades glabrous adaxially. Inflorescences unispicate and multispicate (often with 1-2 short peduncled lateral spikes of same sex), mostly erect, ellipsoid; primary inflorescence bracts leaflike, rarely scalelike, equal to or longer than inflorescences. Scales red-brown to purple, lanceolate, to 3 × 1 mm, shorter than perigynia, margins hyaline, central midrib extending to scale apex, apex acute. Perigynia purple-black, lanceolate, (2.5-)3(-4) × (1-)1.6(-2.5) mm, narrower than subtending scale, apex tapering, distal 1/3 with few short hairs; beak 0.5 mm, orifice oblique; rachilla absent. Achenes to 2.8 × 1.4 mm, loosely enveloped by perigynia, occupying 1/3-2/3 width and 1/3-3/4 length of perigynia. 2n = 58.

Fruiting late May-Jul. Serpentine soils; 1000-2000 m; Calif., Oreg.

The type locality for Carex scabriuscula is not known. Type specimens refer only to a wet meadow in the Cascade range. Searches, using information from Cusick´s notebooks, have not relocated the species in the Cascades.

The sectional alignment of this taxon also is problematic. Historically, it has been placed in the Scirpinae; ongoing research suggests it should be excluded from the section based on its atypical pubescence, chromosome number, leaf anatomy, multispicate inflorescences, and unique achene micromorphology.