Torr. in W.H.Emory, Rep. U.S. Mex. Bound. 2(1): 223 (1858)
T: New Mexico, near the Copper Mines, Bigelow.
Perennials, c. 20–35 (–55) cm tall, loosely caespitose; rhizome long, creeping, to 1.5 mm in diam., with internodes long; stolons ascending. Stem subterete to slightly compressed, usually ±papillose. Cataphylls 1–2, dull brownish, to c. 5 cm long; basal leaves few; cauline leaves 2–3, blades flat, c. 3–14 cm long (upper shorter), 1.5–2.5 mm wide; margins often papillose; apex subulate; sheaths narrow, with broad membranous margins; auricles distinct, 1.0–2.0 mm long, broadly obtuse or truncate. Lower bract reduced, pale brownish-subherbaceous, c. 1–2 cm long, shorter than inflorescence. Inflorescence of (1–) 2–4 (–7) subcongested or variably pedunculate cup-shaped to ±hemispherical (2–) 4–7-flowered heads (if heads congested then compound heads to 15-flowered); peduncles to 5–6 cm long, usually shorter. Upper bracts ovate, acuminate, to 6 mm long, ±scarious. Tepals subequal, ovate-lanceolate, conspicuously broadly membranous-bordered; outer tepals subacute; inner tepals subobtuse and often mucronate, c. 4.5–6.0 mm long, with central band green becoming pale brownish, distinctly narrowly bordered castaneous. Stamens 6; anthers 1.1–1.7 mm long; filaments 0.6–1.0 mm long; style 0.7–0.9 mm long; stigmas 1.5–2.5 mm long. Capsule trilocular, narrowly ovoid-trigonous, ±equalling perianth, c. 3.5–4.8 mm long, castaneous-brown above, obtuse to subtruncate; mucro to 0.3 (–0.5) mm long. Seeds obliquely narrowly ovoid, pale brown, apiculate, c. 0.50–0.65 × c. 0.25 mm, indistinctly reticulate; appendages ±absent or inconspicuous. 2n = 40, fide Á.Löve & D.Löve, Taxon 30: 849 (1981). Fig. 57.