(Engelm.) Coville, Mem. Torrey Bot. Club 17: 106 (1894)
Perennials, 35–80 (–100) cm tall; rhizome creeping, 2–4 mm in diam., with internodes c. 0.5–1.0 cm long. Stems in rows, forming loose stands, terete, 1.5–2.5 mm in diam., smooth, or slightly striate when dry; subepidermal sclerenchyma strands present; ridges c. 25–35; pith continuous, of astericiform cells. Basal cataphylls 1–2, ovate, red-brown to stramineous, shiny; other cataphylls 2–3, red-brown at base, otherwise stramineous to greenish, with longest one c. 5–9 cm long, tight, not shiny, with a short acicular blade. Lower bract erect, an apparent prolongation of stem, c. 10–25 cm long, much exceeding inflorescence. Inflorescence ±loose, 8–30 (–50)-flowered, 1.5–4 cm long, usually of 2–6 main branches, flowers usually on distinct pedicels. Bracteoles broadly ovate, c. 1 mm long, membranous to scarious. Tepals subequal, ±appressed to capsule, ovate-lanceolate; outer tepals 1.8–2.5 mm long, ±acute; inner tepals to c. 2.2 mm long, acute to obtuse and mucronate; central band prominent, light brown to greenish-brown; margins broad, ±scarious. Stamens 6; anthers 0.5–0.7 mm long; filaments 1.0–1.3 mm long; style 0.3–0.5 mm long; stigmas c. 1 mm long. Capsule trilocular, ovoid, subobtuse, conspicuously exceeding perianth, 2.4–3.2 mm long including a broad-based c. 0.3 mm rostrum, shiny, pale brown to brown. Seeds ovoid, apiculate, c. 0.7–0.9 × 0.2–0.3 mm including loose apices of outer seed coat, indistinctly reticulate.