Plants loosely cespitose; rhizomes horizontally spreading, pale brown to reddish brown, (5-)20-80 mm, slender. Culms 7-55 cm, scabrous distally; bases (remnants of old leaves) fibrous. Leaf blades pale to dark green, 0.7-3.6 mm wide, herbaceous, papillose to scabrous abaxially, papillose to scabrous adaxially, blades of distal cauline leaves poorly developed. Inflorescences with both staminate and pistillate spikes; peduncles of staminate spikes 0.7-13 mm; proximal nonbasal bracts leaflike, shorter than inflorescences. Spikes: proximal pistillate spikes 1-3 (basal spikes 0); cauline spikes overlapping or somewhat separated, with (2-)3-13 perigynia; staminate spikes 8-22.5 × 1.4-4.6 mm. Scales: pistillate scales pale or usually dark reddish brown, with narrow white margins, ovate to lanceolate, 2.7-4.3 × 0.8-2.4 mm, apex acute to long-acuminate; staminate scales obovate to lanceolate, 3.7-6.1 × 1-1.4 mm, obtuse to acute or acuminate. Anthers 1.9-4.6 mm. Perigynia yellowish green to pale olive, veinless, obovoid, 2.7-4.6 × 1.2-1.7 mm, as long as wide; beak straight, pale green to olive, occasionally with reddish brown tinge near apex, 0.9-1.6 mm, weakly ciliate-serrulate, apical teeth 0.1-0.6 mm. Stigmas 3. Achenes dark brown, obovoid to globose, obtusely trigonous in cross section, 1.3-2.2 × 0.9-1.6 mm.