Cyperus lancastriensis Porter ex A. Gray
Family: Cyperaceae
Many-Flower Flat Sedge
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Herbs, perennial, cespitose, with inconspicuous, short rhizomes scarcely visible between culm bases. Culms basally cormlike, trigonous, (10-)20-80 cm × 1-3 mm, glabrous. Leaves inversely W-shaped, 20-70 cm × 5-11 mm, adaxial surface, margins minutely scabridulous. Inflorescences: spikes densely ellipsoid to obovoid, 2.5-4.3 × 1.5-3 cm; rays 5-10, 4-20 cm, glabrous; rachis 7-14 mm; bracts 3-8, horizontal to ascending at 45°, flat, 5-35 cm × 2.5-6 mm; rachilla persistent, wings 0.5 mm wide. Spikelets 50-90, linear-lanceoloid to linear-subulate, ± terete-quadrangular, (11-)12-13(-15) × 1.1-1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 3-6(-8), appressed, whitish green or often yellow-tinted, sometimes reddish striate, laterally 4-ribbed, ovate-lanceolate, (3.9-)4.2-4.6(-4.8) × 1.6-2 mm. Flowers: anthers 0.7-1 mm; styles 1-1.5 mm; stigmas 2-3 mm. Achenes yellowish brown to brown, ± stipitate, conspicuously falcate, 3-4 times long as wide, oblong, 2.2-2.6 × 0.6-0.7 mm, apex obtuse, surfaces puncticulate.

Fruiting summer (Jul-Aug). Disturbed, sunny or partly shaded places in mesic or dry-mesic soils, often on riverbanks and flood plains; 0-800 m; Ala., Ark., Del., D.C., Fla., Ga., Ky., Md., Mo., N.J., N.C., Ohio, Pa., S.C., Tenn., Va., W.Va.

Stout perennial 3-9 dm with short, knotty rhizomes; lvs 4-10 mm wide, usually shorter than the stem; at least the lowest bract surpassing the infl; rays several, usually well developed, to 12 cm; spikes unbranched, short-cylindric, rounded at both ends, 1-3 cm; spikelets 50-100+, horizontally radiating except the uppermost and lowermost, subulate, 3-8-fld, acuminate, deciduous at maturity; scales oblong, 4-5 mm, appressed, finely multiribbed, obtuse, the tip of one reaching well beyond the base of the next one on the same side; anthers 0.7-1 mm; achenes trigonously obovoid-oblong, 2-2.6 mm, a third as thick, held between the hyaline wings of the rachilla. Woods and fields, N.J. to W.Va., O., and Mo., s. to Ga. 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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