Perennials, (40–) 60–100 (–140) cm tall, densely caespitose; rhizome very short-noded. Cataphylls 3–5, with longest 10–20 cm long, not glossy, ±tight with overlapping margins, usually blackish to dark reddish-brown at base abaxially, greenish to stramineous-brown above, adaxially silvery stramineous. Stem leafless, terete, 1–2 mm thick, ±hard, dark green; ridges 10–20, conspicuous, with subepidermal sclerenchyma strands not above the largest vascular bundles, and with enlarged cells on the ridges; vascular bundles in one ring; pith of astericiform cells, continuous. Lower bract 10–20 cm long, much exceeding the inflorescence; sheath slightly widened, slightly constricted below; margins to 5 mm wide, scarious. Inflorescence (1–) 2–3 (–5) cm long, lax to compact; flowers many, solitary or densely aggregated. Bracteoles ovate, c. 1–1.5 mm long, scarious to stramineous. Tepals subequal, with outer ones slightly longer, 2–3 (–3.5) mm long, lanceolate, acuminate-cuspidate, pale brown; tip of outer tepals often reflexed. Stamens 3 (–6); anthers 0.5–0.7 mm long; filaments 0.5–0.9 mm long; style c. 0.1 mm long; stigmas to 1.0 mm long. Capsule triseptate, broadly trigonous-ovoid, 2–2.5 mm long, shorter than to slightly exceeding perianth, obtuse to retuse, not mucronate, pale brown to medium brown. Seeds 0.3–0.4 (–0.5) mm long, obliquely obovoid, striate-reticulate, brown; appendages absent. 2n = 40, fide N.A.Harriman & D.Redmond, Rhodora 78: 731 (1976), as J. effusus.