(Engelm.) Coville, Bull. Torrey Bot. Club 22: 305 (1895)
Perennials, 40–100 cm tall, rhizomatous or subcaespitose. Rhizomes short-creeping, 2 mm in diam., not tuberous, horizontal, branched. Cataphylls absent; basal leaves 2–3 (–6), 9–70 cm long. Cauline leaves 1–4, 9–70 cm long, laterally compressed, 2–4.5 (–6) mm wide, septate (septa ±distinct externally in dry condition), unitubular; tip acute; auricles 1–3 mm long, acute, membranous. Lower bract leaf-like, green becoming castaneous, linear, 5–10 cm long, shorter than the inflorescence, erect or more commonly spreading to reflexed; other bracts castaneous, linear to lanceolate, 0.9–3 mm long. Inflorescence panicles of 10–30 heads, (2–) 5–30 cm tall, with spreading branches; heads spherical, (6–) 15–30-flowered, (10–) 12–15 mm in diam. Tepals equal, lanceolate-subulate, green to reddish, acuminate, 3.8–5 mm long. Stamens 3, not exserted; anthers 0.5–0.6 mm long; filaments 1.2–1.8 mm long; style ±absent, c. 0.1 mm long; stigmas 0.3–0.4 mm long. Capsules unilocular, lanceolate in outline, tapering to a subulate tip, 4–5.5 mm, stramineous, much exceeding perianth; valves separating or not at dehiscence. Seeds ovoid to broadly ovoid, apiculate, 0.4–0.6 × 0.2–0.3 mm, pale brown, reticulate; appendages absent.