Cyperus pringlei Britton; C. tetragonus var. pringlei (Britton) Kükenthal; Mariscus tetragonus (Elliott) C. B. Clarke

Herbs, perennial, cespitose, rhizomatous. Culms trigonous, (20–) 30–80 cm × 1–2.5 mm, glabrous or occasionally with scattered prickles on distal angles. Leaves 9–11, flat to slightly V-shaped, 25–80 cm × 3.5–10 mm. Inflorescences: spikes (1–)3–6, loosely cylindric or oblong with parallel sides, 1.5–4 cm × 10–17 mm; rays 6–12, 2–25 cm, glabrous or rarely scabridulous proximal to spikes; bracts 6–11, ascending at 45°, flat, (1–)10–20(–26) cm × 1–10 mm; rachilla deciduous, wings persistent, 0.4–0.5 mm wide. Spikelets 10–60, narrowly ellipsoid, quadrangular, 5–8 × 1.5–2 mm; floral scales persistent, (2–)3–7, appressed, clear at maturity, laterally reddish to purplish brown, medially greenish, often erose at maturity, laterally 3–5-ribbed, medially 3-ribbed, ovate-elliptic, 2.5–3.2 × 1.8–2.1 mm, apex obtuse. Flowers: anthers 0.8–1 mm; styles 0.3–0.5 mm; stigmas 2–2.5 mm. Achenes brown to reddish brown, sessile, oblong-ovoid to broadly ellipsoid, slightly dorsiventrally flattened, 1.8–2 × 0.7–0.8 mm, apex obtuse, apiculate, surfaces papillose to puncticulate.

Fruiting summer–fall (Jun–Nov). Open woods, thickets, barrier islands; 0–1000 m; Ala., Ariz., Fla., Ga., Miss., N.Mex., N.C.

The status of Cyperus pringlei from the southwestern United States requires further study.