Cyperus refractus

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.

Fruiting summer (Jul-Aug). Sandy riverbanks, gravelly roadsides, pastures, disturbed places; 20-300 m; Ala., Ark., D.C., Ga., Md., Mo., N.C., Pa., S.C., Tenn., Va., W.Va.

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

Stout perennial 3-8 dm, with short, knotty rhizomes; lvs firm, to 10 mm wide, often equaling the stem; longer bracts usually surpassing the infl; rays 4-10, to 15 cm; spikes unbranched, mostly rather loose, short-cylindric, rounded at both ends, 2-5 cm; spikelets 15-50, the upper ascending or erect, the middle spreading, the lower deflexed, subulate, 3-10-fld, 1 mm thick, acuminate, deciduous at maturity; scales 4-6 mm, appressed, finely multiribbed, obtuse, the tip of one reaching just to the base of the next one above on the same side, the lower empty and often more persistent than the others; anthers 1-1.5 mm; achenes trigonously linear-oblong, 2.5-3 mm, held between the broad hyaline wings of the rachilla. Woods and fields; N.J. to O. and Mo., s. to S.C., Ga., Ala., and Ark.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

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