Cyperus pumilus
Cent. Pl. II, 6. 1756.
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.
Phenology: Fruiting spring–summer.
Habitat: Disturbed, sandy soils
Elevation: 0–50 m
Distribution
Fla., West Indies (introduced), Asia, Africa (including Madagascar), Indian Ocean Islands, Pacific Islands, Australia.
Discussion
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.
Selected References
None.