Cyperus articulatus var. multiflorus Kükenthal; C. articulatus var. nodosus (Willdenow) Kükenthal; C. corymbosus Rottbøll var. subnodosus (Nees & Meyen) Kükenthal; C. nodosus Willdenow; C. nodosus var. subnodosus (Nees & Meyen) Boeckeler; C. subnodosus Nees & Meyen

Herbs perennial; rhizomes to 200 cm. Culms to 25 cm apart, 1(–3) together, terete (scarcely compressed in drying), occasionally trigonous for apical 1/3, 40–140(–200) cm, 4–12 mm thick at base, (1.2–)1.5–2.5 mm thick at apex (with conspicuous transverse septa ca. 3 cm apart basally, to 3–5 mm apart apically), glabrous or infrequently scabrid on angles apically; sheaths at base of culm, 2–3, (5–)10–25 cm, loose, papery. Leaves usually bladeless, blades when present, cross ribs prominent, especially adaxially, (1–)10–20(–40) cm × 4–6(–9) mm. Inflorescences: spikes 1(–5), broadly ovoid to ± umbellate, 15–45 × 10–30 mm; rays 5–7(–10), 0.3–8(–12) cm; 2d order rays occasionally present, 5–20 mm; bracts 2(–4), erect, longest appearing to be continuation of culm, deltate to lance-linear, 0.2–2(–9) cm × 1.5–4.5 mm; rachilla persistent, wings translucent, whitish, or stramineous, 0.4 mm wide. Spikelets (1–)5–10, linear, compressed, 10–35(–45) × 1.1–2 mm; floral scales deciduous, 15–45, spreading or appressed, laterally light brown, medially green to brown, laterally 1–2-ribbed, medially 3-ribbed, oblong-elliptic to ovate, 2.9–3.7 × 1.1–1.6(–1.8) mm, apex acute. Flowers: anthers 1.7–2.4 mm; styles 1.2–3.6 mm; stigmas 1.7–6 mm. Achenes brown, stipitate, obovoid-ellipsoid, 1.2–1.6 × 0.4–0.6 mm, stipe 0.1 mm, apex markedly apiculate, surfaces puncticulate.

Fruiting summer. Marshes, shallow water, ditches; 0–100 m; Ala., Fla., Ga., La., Miss., S.C., Tex.; Mexico; Central America; South America; Asia; Africa.

In habit, Cyperus articulatus is reminscent of larger plants of Juncus or Schoenoplectus and is the only North American Cyperus with such a reedlike appearance.