Herb, dioecious, perennial, glabrous, forming dense clumps or diffuse areas of small tufts connected by rhizomes. Rhizome c. 5 mm diam. Cataphylls tan-brown, scarious, extending 4–6 cm up the culm. Culms closely spaced or up to 1 cm apart, erect, flattened (ellipse in cross-section), 40–65 cm long, 1.3–2.1 × 0.8–1.5 mm diam., scarcely rough when fresh but asperous and finely tuberculate when dry, simple; lowest internode long, lowest sheath (2–)5–14 cm above the cataphylls. Sheaths 2 or 3 (rarely 4), persistent, 1.5–4.5 cm long, loose, lax or reflexed, usually with inrolled margins, dull-brown, obtuse to truncate; lamina erect, to c. 1 cm long. Inflorescence 2.5–19 cm long; branches to 6 cm long and moderately crowded with flowers, lower branches spaced further apart on the culm, upper branches more clustered; spathes usually exceeding branches, 1–3 cm long; floral bracts 2, cuspidate. Male flowers: tepals rigid, yellow-brown, lanceolate; outer tepals longer, 3.0–3.6 mm long; inner tepals 2.5–3.0 mm long; filaments c. 2.5 mm long; anthers 1.7 mm long. Female flowers: tepals similar to males; outer tepals 2.6–3.9 mm long; inner tepals 2.6–3.5 mm long. Seeds ellipsoidal, 1.2 mm long, finely colliculate with pattern of small raised areas.
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