Plants (25–) 40–120 (–150) cm tall, forming ±dense stands; rhizome usually short-noded. Cataphylls 3–4, usually lax, less often ±tight, abaxially stramineous-brown distally, usually dull (rarely slightly glossy) castaneous at base; upper cataphylls c. 7–15 cm long, with short awn-like blade. Stem (0.7–) 1.5–4 mm thick, terete, pale to greyish green, not compressed nor twisted; pith continuous, of astericiform cells, later ±arachnoid. Inflorescence mostly diffuse, (5–) 10–30 (–45)-flowered; main branches straight, c. 0.3–0.4 mm in diam. Bracteoles ovate, 1.5–2.0 (–2.5) mm long, acute, castaneous at least at base. Tepals ±equal, ±narrowly lanceolate; outer tepals often slightly longer, 3.5–5 mm long, acuminate, castaneous with lighter midrib, often becoming stramineous, sometimes ±entirely deep castaneous; inner tepals subobtuse and mucronate or acute. Anthers 1.2–1.8 (–2.2) mm; 2.0–4× as long as 0.4–0.6 (–0.7) mm filaments; style (0.7–) 0.9–1.3 mm long; stigmas c. 2–3 mm long. Capsule oblong-ovoid, trigonous, c. 3.5–4.5 mm long, subequalling perianth, subabruptly narrowing into 0.4–0.7 mm mucro, dark castaneous-brown or brown. Seeds 0.7–0.8 × c. 0.4 mm, faintly reticulate. From Alaska through western N America to S Mexico and Guatemala; distribution imperfectly known. 70: ASK, NWT, YUK. 71: ABT, BRC, SAS. 73: COL, IDA, MNT, ORE, WAS, WYO. 74: KAN, NDA, NEB, OKL, SDA. 76: ARI, CAL, NEV, UTA. 77: NWM, TEX 79: MXC, MXN. 80: GUA. 70. ALASKA: Whittier, 19 Jul 1979, Jörgensen, W16 (LD). YUKON: Kluane Lake, mouth of Slim’s R., H.M.Raup & L.G.Raup 12624 (A, S). 73. COLORADO: Mancos, 8 Jul 1898, C.F.Baker, F.S.Earle & S.M.Tracy 438 (W). OREGON: Harney Co., Edge of Malheur Lake, 3 Jul 1954, Steward 6785 (LD, ORE). WASHINGTON: N of Seattle, Jun 1931, W.J.Eyerdam (LD). WYOMING: Park Co., Beartooth Mtns, Sunlight Basin Rd above Clark’s Fork R., R.G.Stolze 1050 (W). 76. CALIFORNIA: Douglas Co., near Egbert Spring, J.H.Sandberg & J.B.Leiberg 404 (UC, WS). 79. MEXICO CENTRAL: Distrito Federal, San Borjes, 2260 m, F.G.Arséne 10991 (US). 80. GUATEMALA: Huehuetenango, Sierra de los Cuchumatanes N of Tojiah, km 322 on Ruta Nac. 9N, 3200 m, J.H.Beaman 3924 (DUKE, TEX, UC, US).