Cyperus subambiguus Kükenthal var. pallidicolor Kükenthal in H. G. A. Engler, Pflanzenr. 101[IV,20]: 528. 1936

Herbs, perennial, cespitose, rhizomatous. Culms trigonous, (10–) 30–50(–80) cm × (0.8–)1–2 mm, glabrous or occasionally minutely scabridulous on distal angles. Leaves 3–7, M- or V-shaped, (10–)25–40(–55) cm × 2–5 mm, margins and midribs scabridulous or glabrous. Inflorescences: spikes 3–6(–12), grayish to golden brown, loosely cylindric, (6–)10–20(–24) cm × (5–)8–11 mm; rays 0 or 1–3, to 4 cm; rachis glabrous; bracts (3–)4–6(–8), horizontal to strongly reflexed, inversely W-shaped, (3–) 10–20(–30) cm × 1–5 mm; rachilla deciduous, wings persistent, 0.3–0.5 mm wide. Spikelets (10–)25–60(–100), spaced 1–2(–3) mm apart, broadly ellipsoid to oblong, ± terete, 2.4–3.6 × 0.8–1.2 mm; distal spikelet spreading or ascending; floral scales persistent, 1–2(–4), appressed, laterally golden brown to dull grayish white, frequently streaked with red, medially greenish, laterally 3–4-ribbed, medially 3-ribbed, oblong, 2.6–3.3 × 1.8–2.4 mm, apex broadly rounded. Flowers: anthers 0.6–0.8 mm; styles 0.8–1.2(–1.4) mm; stigmas 1.4–2 mm. Achenes reddish brown to dark brown, stipitate, ellipsoid, (1.6–)1.8–2(–2.2) × (0.6–)0.7–0.9 mm, base cuneate to ± attenuate, apex ± acute to broadly rounded, surfaces finely papillose to essentially glabrous.

Fruiting summer. Clearings in montane forests; 800–1200 m; Ariz., N.Mex.; Mexico; Central America; South America.