Volume 6 > Part 4 > Year 1998 > Page 383 > Cyperaceae > Cyperus

44. Cyperus paniceus (Rottb.) Boeckelerwfo-0000379032

Linnaea 36: 381. 1870, ex parte incl. basion.; Kük. in Engl., Pflanzenr. 4(20), 101 Heft: 526. 1936, incl. var. roxburghianus (C.B.Clarke) Kük.; J.Kern in Fl. Males., Ser. 1, Spermat. 7: 6423. 1974, incl. var. roxburghianus; Hô, Câyco Vietnam III. 2: 696. 1993, incl. var. roxburghianus.— Kyllinga panicea Rottb., Descr. Icon. Rar. Nov. Pl. 15, t. 4, f. 1. 1773.— Mariscus paniceus (Rottb.) Vahl, En. Pl. 2: 373. 1806; C.B.Clarke in Hook.f., Fl. Br. Ind. 6: 620. 1893, incl. var. roxburghianus C.B.Clarke; III. Cyp.: t. 22, f. 1–2. 1909; T.Koyama, Gard. Bull. Singapore 30: 157. 1977.

Accepted Name : This is currently accepted.

Description : Stoloniferous perennial. Culms usually 1, 8–45(–60) cm by 1–2 mm, trigonous to triquetrous above, smooth, base thickened, fibrous. Leaves: narrowly linear, 7–32 cm by 1–3 mm, long-acute, flattish-plicate; sheaths 0.7–4 cm long, reddish or purplish brown. Involucral bracts 3–5, the longest up to 17 cm long. Inflorescence simple, open to congested or ± capitate, 2–6 by 2–6 cm; primary branches (when present) up to 6, up to 4 cm long; spikes solitary. Spikes cylindric to oblong-cylindric, 0.8–1.5 by 0.4–0.6 cm, terete; axis 0.5–0.8 cm long. Spikelets up to 40 per spike, falling entire, spreading, ovate to lanceolate, slightly recurved, 2.5–3.5 by 0.8–1 mm, ± terete; axis zigzag. Glumes ovate to lanceolate, 1–3.5 by 1.4–1.7 mm, acute, sides membranous, 2–5-nerved, whitish to brownish, keel obtuse, 3-nerved, greenish grey. Stamens 2–3; anthers 0.7–0.8 mm long. Stigmas 3. Nutlets 1 per spikelet, ellipsoid-cylindric, trigonous, 1.8–2.2 by 0.6–0.8 mm, yellowish brown, minutely punctate.

Thailand : NORTHERN: Mae Hong Son, Chiang Mai (Chom Thong), Chiang Rai (Mae Chan), Tak (Ban Lansang, Wangchao); NORTH-EASTERN: Mukdahan; EASTERN: Nakhon Ratchasima (Ban Chumsaeng), Surin (Rattana); SOUTH-WESTERN: Kanchanaburi (Ta Salao).

Distribution : India (type), Sri Lanka, Indochina, Malesia.

Ecology : Grasslands, floors of deciduous forests or occasionally margins of rice fields, 100–500 m alt.

Notes: This species differs from Cyperus cyperinus in being a more delicate plant with stolons rather than rhizomes. Also, the spikelets are less than 4 mm long and have only one nutlet. Cyperus paniceus is often divided into var. paniceus and var. roxburghianus. However, field observations by T. Koyama in Sri Lanka show that the variation between the two taxa is continuous and therefore we have reduced var. roxburghianus here to synonymy.