Cyperus refractus Engelm. ex Boeckeler

Cyperus refractus is often mistaken for C. strigosus, which has shorter anthers (0.4–0.5 mm) and spreading, ± deciduous floral scales.

Herbs, perennial, cespitose, with inconspicuous, short rhizomes scarcely visible between culm bases. Culms basally cormlike, trigonous, 30–100 cm × 2–4 mm, glabrous. Leaves V-shaped to flat, 20–70 cm × 3–8 mm, adaxial surface, margins minutely scab-ridulous. Inflorescences: spikes loose, broadly ellipsoid to ovoid, 4–7 × 2–6 cm; rays 6–13(–16), 4–25 cm, glabrous; rachis 1.5–3 cm; bracts 3–6, horizontal to ascending at 30°, flat, 5–35 cm × 2.5–6 mm; rachilla persistent, wings 0.4–0.5 mm wide. Spikelets (13–)20–60(–74), linear, ± terete, (11–)13–25(–28) × 1.2–1.5 mm; distal spikelets spreading or ascending; floral scales persistent, (2–)3–6, stramineous, red-purple striate, laterally 3–5-ribbed, ovate-lanceolate, 4.5–5.3 × 1.2–1.5 mm. Flowers: anthers 1–1.5 mm; styles 1.5 mm; stigmas 1.5 mm. Achenes brown to purplish brown, oblong-linear (5–6 times long as wide), 2.6–3 × 0.5–0.6 mm, base cuneate, apex obtuse, surfaces puncticulate.

Ala., Ark., D.C., Ga., Md., Mo., N.C., Pa., S.C., Tenn., Va., W.Va.

Fruiting summer (Jul–Aug).

Sandy riverbanks, gravelly roadsides, pastures, disturbed places; 20–300m.

Cyperus refractus is a species of sedge that is native to south eastern parts of North America.

Cyperus refractus adalah spesies tumbuhan yang tergolong ke dalam famili Cyperaceae. Spesies ini juga merupakan bagian dari ordo Poales. Spesies Cyperus refractus sendiri merupakan bagian dari genus Cyperus. Nama ilmiah dari spesies ini pertama kali diterbitkan oleh Engelm. ex Boeckeler.

Cyperus refractus là loài thực vật có hoa trong họ Cói. Loài này được Engelm. ex Boeckeler mô tả khoa học đầu tiên năm 1870.