Cyperus baldwinii Torrey; C. cyclostachyus Grisebach; C. echinatus (Linnaeus) Alph. Wood var. multiflora Chapman; C. globulosus Aublet var. pseudofiliculmis Kükenthal; C. globulosus var. robustus (Boeckeler) Shinners; C. plankii Brittton; C. retrorsus Chapman var. robustus Kükenthal; Mariscus bracheilema Steudel; M. brittonii C. B. Clarke

Herbs perennial, cespitose. Culms trigonous, (4–)14–45 cm × 1–2 mm, glabrous. Leaves yellow-green, flat, 18–44 cm × 3–4.5 mm. Inflorescences: spikes densely to loosely globose to ovoid, 10–20 mm wide; rays (3–)5–9(–14), 1–15(–26) cm; rachis 3–6(–9) mm; bracts (4–)6–9(–11), horizontal to ascending at 45°, flat, 1–30 cm × 0.5–4 mm; rachilla deciduous, wings persistent, 0.3–0.5(–0.8) mm wide. Spikelets (10–)30–50, oblong to lanceoloid, quadrangular to subterete, compressed, 4–8 × 1–1.3 mm; distal spikelet spreading or ascending; floral scales persistent, (1–)2–4(–6), appressed, whitish with red speckles, laterally 2–4-ribbed, ovate, 2.3–3.6 × 1.8–2.2 mm. Flowers: anthers 0.5 mm; styles 0.6–1.3 mm; stigmas 1.2–2.6 mm. Achenes reddish brown to nearly black, sessile, oblong, ellipsoid, 2–2.4 × 0.4–0.5(–0.7) mm, apex ± truncate-emarginate, apiculate, surfaces puncticulate.

Fruiting summer–early fall. Disturbed, sunny areas, coastal rocks, moist thickets; 0–200 m; Ala., Ark., Del., Fla., Ga., La., Md., Miss., Mo., N.J., N.C., Okla., Pa., S.C., Tenn., Tex., Va., W.Va.; Mexico; West Indies; Central America; South America (Venezuela).

Cyperus globulosus Aublet is a synonym of C. luzulae (Linnaeus) Rottbøll ex Retzius, which is a widespread neotropical species, and it has long been misapplied to Cyperus croceus (G. C. Tucker 1987).