Mariscus pubescens J. Presl & C. Presl 1828, not Cyperus pubescens Steudel 1854; C. flavomariscus Grisebach var. peduncularis Britton; C. flavus (Britton) Kükenthal var. peduncularis (Britton) Kükenthal

Herbs, perennial, cespitose, shortly rhizomatous. Culms 1–4, trigonous, (2–)20–50(–80) cm × (0.8–)1.5–2(–2.8) mm, basally glabrous or nearly so, apically hispidulous, on faces and angles distally, especially so immediately proximal to bracts. Leaves 2–5(–7), V-shaped, (5–)15–30(–45) cm × (1.5–)2.5–5(–8) mm. Inflorescences: spike 1 (occasionally 1–2 smaller sessile spikes at base), densely cylindric, (7–)11–20(–25) × (5–) 7–10(–12) mm; rays 3–6(–10), (1–)3–6(–18) cm, rays and rachis hispidulous; bracts 4–8(–10), ascending at 30–60°, V-shaped, (2–)10–25(–45) cm × (1–)3–6(–8) mm; rachilla deciduous, wings persistent, 0.3–0.4 mm wide. Spikelets (20–)70–120(–140), oblong-ellipsoid to oblong-lanceoloid, ± terete to quadrangular, (2.2–)3.4–4.5(–5.6) × (0.8–)0.9–1.2(–1.3) mm; distal spikelet spreading or ascending; floral scales 1(–3), appressed, stramineous, red-spotted, strongly 3(–4)-ribbed on either side of green part, medially weakly 3-ribbed, ovate to elliptic ovate, (2.4–)2.8–3.3(–3.6) × 1.6–2 mm, apex acute, mucronulate from excurrent midrib. Flowers: anthers (0.3–)0.4–0.6 mm; styles 0.4–0.6(–0.8) mm; stigmas 1–1.4 mm. Achenes brown, stipitate, ellipsoid, (1.6–)1.8–2 × (0.7–) 0.8–0.9 mm, stipe 0.1–0.2 × 0.2 mm, apex ± truncate, apiculate, surfaces puncticulate to glabrous.

Fruiting mid summer–fall (Jul–Sep). Various dry, open environments; 500–1000 m; Ariz.; Mexico; Central America; South America.

Cyperus dentoniae was not treated in G. Kükenthal’s monograph (1935–1936), apparently because he did not see any materials of the species. The plant has been treated as “C. asper (Liebmann) O’Neill,” a name based on Mariscus asper Liebmann and a synonym of C. mutisii (A. B. Ayers 1946).