Volume 6 > Part 4 > Year 1998 > Page 365 > Cyperaceae > Cyperus

23. Cyperus involucratus Rottb.wfo-0000375418

Descr. Pl. Rar.: 22 (1772); Hô, Câyco Viêtnam III. 2: 682. 1993.

Accepted Name : Cyperus alternifolius subsp. flabelliformis (Rottb.) Kük.
Pflanzenr. 4(20), 101 Heft: 193. 1936; T.Koyama, Gard. Bull. Singapore 30: 140. 1977.

Synonyms & Citations :

Description : Rhizomatous perennial. Culms tufted, 50–170 cm by 5–10 mm, trigonous to ± terete at base, scabrous below inflorescence. Leaves reduced to basal sheath; sheath 10–20 cm long, pale greenish to yellow brown, apex obliquely truncate. Involucral bracts 15 or more, ± equal, 20–50 cm by 5–15 mm. Inflorescence simple to compound, 9–12 by 15–30 cm; primary branches numerous, ± equal, 7–10 cm long; secondary branches 1–1.5 cm long. Spikelets in clusters of 3–10, oblong-lanceolate to elliptic, 3–9 by 1.7–3 mm, flattened; axis straight. Glumes ovate, 1.8–2 by 1.2–1.5 mm, acute, sides membranous, 3–5-nerved, pale green sometimes tinged with rusty brown, keel acute, greenish to pale brown. Stamens 3; anthers 1 mm long. Stigmas 3. Nutlets obovoid-ellipsoid, trigonous, 0.6–0.8 by 0.5 mm, maturing brown, minutely punctate.

Thailand : CENTRAL: Krung Thep Maha Nakhon (Bangkok); PENINSULAR: Narathiwat (To Daeng).

Distribution : Native to tropical Africa and the Middle East (Arabia – type). Widely cultivated as an ornamental.

Ecology : Open grassy places, waysides, waste places, rice fields.

Notes: This species is characterised by its large number (15 or more) involucral bracts of similar length. The glumes are pale green.