Mutis' Flat Sedge

Cyperus mutisii is recognized by its cylindric spikes borne digitately at the ends of the rays and its short, plump spikelets. As spikelets mature, the floral scales, having erose margins contrasting with the brownish sides, beome useful distinguishing features.

Herbs, perennial, cespitose, rhizomatous. Culms trigonous, (20–)30–120 cm × 1.4–3.5 mm, glabrous or occasionally with scattered prickles on distal angles. Leaves 2–4(–6), inversely W-shaped, 10–60(–70) cm × (2–)4–13 mm, margins and midribs scabridulous or glabrous. Inflorescences: spikes (1–)3–6, narrowly cylindric, 1–4(–6) cm × 5–11 mm; rays 0 or 3–6, 2–23 cm; bracts 5–8, ascending at ± 45°, inversely W-shaped, (4–) 14–40(–46) cm × 1–12 mm; rachilla deciduous, wings persistent, 0.3–0.5 mm wide. Spikelets 35–100, oblong-ellipsoid, ± terete, elliptic in cross section, 3–7 × (0.9–) 1.3–2 mm; distal spikelets spreading or ascending; floral scales persistent, 1–2(–5), appressed, becoming clear at maturity, laterally brownish to reddish brown, medially greenish, laterally 3–5-ribbed, medially 3-ribbed, often erose at maturity, ovate to elliptic, 2.2–3.2 × 1.5–2.1 mm, apex obtuse. Flowers: anthers 0.6–0.8 mm; styles 0.4–0.8 mm; stigmas 1.2–2.2 mm. Achenes brown to reddish brown, sessile, broadly ellipsoid, slightly dorsiventrally flattened, 1.5–1.8 × 0.7–0.9(–1) mm, apex obtuse, apiculate, surfaces papillose to puncticulate.

Ariz.; Mexico; Central America; South America.

Fruiting summer–fall (Jun–Nov).

Clearings in montane forests, canyons; 500–1500m.

Mariscus mutisii Kunth in A. von Humboldt et al., Nov. Gen. Sp. 1: 216, plate 66. 1816; Cyperus asper (Liebmann) O’Neill; C. compresso triqueter Boeckeler; C. ehrenbergianus Boeckeler; C. mutisii var. asper (Liebmann) Kükenthal; C. mutisii var. contractus Kükenthal; C. mutisii var. semitribrachiatus (Boeckeler) Kükenthal; C. ochreatus Boeckeler; C. semitribrachiatus Boeckeler; Mariscus asper Liebmann

Cyperus mutisii is a species of sedge that is native to parts of southern parts of North America, throughout Central America and in northern parts of South America.