Cyperus hystricinus Fernald

Cyperus hystricinus resembles C. plukenetii and C. retrofractus; it can be readily distinguished from both by its glabrous culms. Overly mature specimens of C. lancastriensis are frequently misidentified as C. hystricinus; C. hystricinus may be confirmed by its narrow, nearly glabrous leaves and bracts, golden brown spikelets, longer, narrower achenes, and elongated rhizome internodes (to 15 mm vs. 5 mm in 76. C. lancastriensis).

Herbs, perennial, cespitose, with well-developed rhizomes. Culms trigonous, 30–100 cm × 2–4 mm, basally cormlike, glabrous. Leaves flat to broadly V-shaped, 20–70 cm × 4–6 mm, glabrous except for marginal prickles. Inflorescences: spikes loosely to densely ovoid, oblong (2 times long as wide), 10–12 × 6–9 mm; rays 6–11, 1–16 cm, glabrous; bracts 5–10, ascending at 30–45°, flat, 6–25 cm × 3–6 mm; rachilla persistent, wings 0.5 mm wide, covering nearly entire length of achene. Spikelets (20–)40–100(–120), proximal spikelets reflexed somewhat, distal ones divaricate, ± terete, lanceoloid, 6–6.8 × 1–1.4 mm; floral scales persistent, 1–2(–3), appressed, golden brown, lanceolate, laterally 5–6-ribbed, 3.8–4.9 × 1.4–1.6 mm, apex mucronate, mucro at most 0.3 mm. Flowers: anthers 1–1.3 mm; styles 0.8–1 mm; stigmas 2–3 mm. Achenes brown, sessile, linear, 2.5–2.8 × 0.5–0.7 mm, apex obtuse, apiculate, surfaces muriculate.

Ala., Ark., Del., D.C., Ga., La., Md., Miss., Mo., N.J., N.C., Tex., Va.

Fruiting late summer–early fall (Jul–Sep).

Xeric, sandy soils of sand hills and pine barrens; 0–200m.

Cyperus retrofractus (Linnaeus) Torrey var. hystricinus (Fernald) Kükenthal

Cyperus hystricinus is a species of sedge that is native to southern parts of North America.