Pine Barren Flatsedge

Cyperus retrorsus was reported in Indiana (M. L. Horvat 1941); we have been unable to confirm the report.

Herbs, perennial, cespitose, shortly rhizomatous. Culms trigonous, 20–50(–85) cm × 1–2(–4) mm, glabrous. Leaves 3–6(–10), 10–40(–55) cm × 1.5–4(–5) mm, V- to inversely W-shaped. Inflorescence: spike 1, densely oblong-ovoid often with small basal branches, 8–16 × 4–12(–16) mm; rays 4–8(–11), 0.5–3.5(–8.5) cm; bracts (3–)4–6(–10), ascending at (30–)45°, flat to broadly V-shaped, (4–)14–30(–55) cm × 1–5 mm, scabridulous along margins only; rachilla deciduous, wings persistent, 0.2–0.3 mm wide. Spikelets 40–120, oblong-lanceoloid, subterete, 2.2–4(–4.5) × 0.8–1.6 mm; distal spikelet spreading or ascending; floral scales persistent, 2–5, appressed, brown to stramineous, or fuscous and lustrous, medially greenish and 1(–3)-ribbed, laterally greenish to yellowish white and 3–4-ribbed, oblong to oblong-lanceolate, 1.8–2.5 × 1–1.5 mm, subcoriacous. Flowers: anthers 0.3–0.5 mm; styles 0.5–0.8 mm; stigmas 0.6–0.9 mm. Achenes brown, oblong-ellipsoid, 1.2–1.7 × 0.5–0.6 mm, base cuneate, apex subacute, surfaces papillose.

Ala., Ark., Del., D.C., Fla., Ga., La., Md., Miss., Mo., N.J., N.Y., N.C., Okla., S.C., Tenn., Tex., Va.; Mexico (Tamaulipas).

Fruiting summer (Jun–Aug).

Open woods and thickets in moist to dry, sandy soils; 0–1000m.

Mariscus cylindricus Elliott, Sketch Bot. S. Carolina 1: 74. 1816; Cyperus cylindricus (Elliott) Britton 1879, not Boeckeler 1859; Mariscus retrorsus (Chapman) C. B. Clarke

Cyperus retrorsus, commonly called pine barren flatsedge, is a species of flowering plant in the sedge family (Cyperaceae). It is found primarily in the Southeastern United States, with a range extending north to Martha's Vineyard, Massachusetts and south to Tamaulipas, Mexico. Its natural habitat is in dry sandy soils, in open woodlands and thickets.

Cyperus retrorsus is a tufted perennial, growing to around 50 cm tall. Its fruits mature in the summer. It is similar to the closely related C. echinatus, from which C. retrorsus can be distinguished by its cylindrical inflorescence and shorter stature.