Volume 6 > Part 4 > Year 1998 > Page 393 > Cyperaceae > Pycreus

5. Pycreus flavidus (Retz.) T.Koyamawfo-0000506118

J. Jap. Bot. 51: 316. 1976; Gard. Bull. Singapore 30: 150. 1977.

Accepted Name : Cyperus flavidus Retz.
Obs. Bot. 5: 13. 1788; J.Kern in Fl. Males., Ser. 1, Spermat. 7: 648. 1974; Hô, Câyco Viêtnam III. 2: 693. 1993.

Synonyms & Citations :

Description : Annual or perennial. Culms densely tufted, 8–60 cm by 1–1.5 mm, trigonous, smooth. Leaves: blade narrowly linear to setaceous, 2–24 cm by 1–2 mm, acuminate, flattish plicate or canaliculate; sheath 1–10 cm long, reddish brown. Involucral bracts 2–4, the longest up to 25 cm long. Inflorescence simple, open or congested and appearing ± capitate; primary branches 1–6, 0.5–7 cm long. Spikes broadly ovoid to ± globose, 1–3 by 1.2–4 cm; axis 0.1–1 cm long. Spikelets 5–20 per spike, spreading, linear or linear oblong, 6–30 by 1.5–3 mm, axis straight. Glumes oblong-ovate, 1.5–2.5 by 1–1.5 mm, narrowly obtuse, sides chartaceous, nerves 0, pale brown to dark reddish brown, shiny, margins pale-hyaline, keel acute, 3-nerved, greenish. Stamens 2; anthers 0.5 mm long. Nutlets narrowly obovate to oblong-elliptic, 0.8–1.2 by 0.4–0.6 mm, maturing dark brown, minutely punctate.

Thailand : NORTHERN: Mae Hong Son (Mae Sariang), Chiang Mai (Ban Mae Hae, Doi Inthanon, Doi Suthep), Nan, Phrae (Mae Khaen), Tak (Wang Chao); NORTH-EASTERN: Loei (Phu Kradueng), Sakon Nakhon (Phu Phan), Nakhon Phanom (Paknam Songkran); SOUTH-WESTERN: Kanchanaburi.

Distribution : Old World tropics (India – type) and temperate regions.

Ecology : Open wet places, rice fields and margins of rivers, swamps and ponds, 100–1,700 m alt.