33. Cyperus pumilus Linnaeus, Cent. Pl. II. 6. 1756.
Cyperus leucolepis J. Carey ex C. B. Clarke; Juncellus leucolepis (J. Carey ex C. B. Clarke) C. B. Clarke; Pycreus pumilus (Linnaeus) Domin
Herbs, annual, cespitose. Culms trigonous, 1–35 cm × 0.5–1 mm, glabrous. Leaves flat, 5–20 cm × 1–2 mm. Inflorescences: heads ± digitate, 8–26 mm diam.; rays 1–6, 0.5–5 cm; bracts 3–4, ± horizontal, flat, 3–18 cm × 1–2 mm. Spikelets 6–25, ovoid to linear-lanceoloid, compressed, 4–15 × 1–2 mm; floral scales 8–28(–40), clear, laterally ribless, ovate, 1.4–1.6 × 0.8 mm, apex awned, awn excurved, 0.3–0.5 mm. Flowers: stamens 1–2; anthers 0.2 mm; styles 0.5 mm; stigmas 0.3 mm. Achenes dark brown to black, sessile, obovoid, 0.6 × 0.4 mm, apex obtuse, apiculate, surfaces minutely punctate.
Fruiting spring–summer. Disturbed, sandy soils; 0–50 m; introduced; Fla.; West Indies (introduced); Asia; Africa (including Madagascar); Indian Ocean Islands; Pacific Islands; Australia.
Cyperus pumilus is distinctive because it is our only distigmatic Cyperus with awned floral scales.
Cyperus hyalinus Vahl, a southeastern Asian and Australian species, has recently been collected in Miami-Dade County, Florida (Mears s.n., EIU, VSC). This is an aberrant species sometimes placed in the monotypic genus Queenslandiella as Q. hyalina (Vahl) F. Ballard; it differs from C. pumilus in having deciduous rachillae as well as deciduous floral scales.