Cyperus fugax


Kongel. Danske Vidensk. Selsk. Skr., Naturvidensk. Math. Afd., ser. 5, 2: 196. 1850.

Basionym: Cyperus tenellus J. Presl & C. Presl 1828
Synonyms: Cyperus inconspicuus Liebmann
Treatment appears in FNA Volume 23. Treatment on page 159. Mentioned on page 142, 160.

Herbs, annual, cespitose. Culms (1–)10–30(–60) together, roundly trigonous proximally, trigonous distally, (0.5–)3–6(–12) cm × (0.2–)0.4–0.8 mm, glabrous. Leaves V-shaped, (1–)3–5(–10) cm × (0.5–)1–2 mm. Inflorescences: spikes loosely ovoid, 8–15(–25) mm wide; rachis 1–3 mm; rays (1–)2–4(–6), (0.5–)1–3(–6) cm; 2d order rays absent; bracts (1–)2–4(–5), ascending at 30–45°, V-shaped, (1–)2.5–6(–11) cm × 0.5–1.8 mm. Spikelets (2–)4–6(–10), linear-lanceoloid, strongly flattened, (5–)8–12(–18) × 1.2–1.5 (1.8) mm; floral scales (5–)10–16(–32), laterally clear, stramineous or light reddish brown, medially green, laterally ribless, medially 3(–5)-ribbed, ovate, (1.2–)1.3–1.6(–2) × 1–1.2(–1.4) mm, apex obtuse, mucronate to minutely mucronulate. Flowers: stamens 2; anthers 0.1–0.2 mm; styles 0.1–0.3(–0.4) mm; stigmas 0.3–0.4 mm. Achenes light to dark brown, glossy or iridescent, stipitate, oblong-obovoid, 0.9–1.1 × 0.4–0.5 mm, stipe 0.1 mm, apex truncate, apiculate, surfaces punctate.

Phenology: Fruiting early summer.
Habitat: Wet, disturbed sandy soils in full sun
Elevation: 0–200 m


V23 251-distribution-map.jpg

La., Tex., West Indies (Cuba), Central America, South America (Ecuador).


Cyperus fugax is known from Louisiana from an early nineteeth century collection from “western Louisiana” (Hale s.n., TCD).

Cyperus fugax has been treated as a form of C. polystachyos (G. Kükenthal 1935–1936; A. B. Ayers 1946); nevertheless, specific status is appropriate. The most conspicuous differences are the annual habit and small size (less than 12 cm) of C. fugax; C. polystachyos is a perennial of moderate size (mostly taller than 20 cm). Other differences are summarized below.

Cyperus polystachyos is characterized as a shortly rhizomatous perennial; floral scales oblong, 1.8–2.4 mm, closely imbricate; styles 0.6–1 mm; stigmas 1.4–2 mm; anthers 0.6–0.8 mm; achenes substipitate to cuneate, slightly compressed laterally.

Cyperus fugax is characterized as a nonrhizomatous annual; floral scales ovate, 1.3–1.6 mm, loosely imbricate; styles 0.1–0.2 mm; stigmas 0.3–0.4 mm; filaments 1.2–1.4 mm; anthers 0.1–0.2 mm; achenes stipitate, strongly compressed laterally.

Selected References


Lower Taxa

... more about "Cyperus fugax"
Gordon C. Tucker* +, Brian G. Marcks* +  and J. Richard Carter * +
Liebmann +
Cyperus tenellus +
La. +, Tex. +, West Indies (Cuba) +, Central America +  and South America (Ecuador). +
0–200 m +
Wet, disturbed sandy soils in full sun +
Fruiting early summer. +
Kongel. Danske Vidensk. Selsk. Skr., Naturvidensk. Math. Afd., ser. +
Illustrated +
Cyperus inconspicuus +
Cyperus fugax +
Cyperus subg. Pycreus +
species +