e-Flora of Thailand
Volume 6 > Part 4 > Year 1998 > Page 351 > Cyperaceae > Cyperus
6. Cyperus digitatus Roxb.wfo-0000371820
(Hort. Beng.: 81: 1814. nom. nud.), Fl. Ind. ed. Carey 1: 209. 1820; C.B.Clarke in Hook.f., Fl. Br. Ind. 6: 618. 1893; Camus in Fl. Gén. I.-C. 7: 74. 1912; Kük. in Engl., Pflanzenr. 4(20), 101 Heft: 55. 1935; J.Kern, Reinwardtia 6: 51. 1961; in Fl. Males., Ser. 1, Spermat. 7: 601. 1974; T.Koyama, Gard. Bull. Singapore 30: 127. 1977; Hô, Câyco Viêtnam III. 2: 673. 1993.
Accepted Name : This is currently accepted.
Synonyms & Citations :
Description : Shortly rhizomatous perennial. Culms tufted or solitary, 60–200 cm by 3–7 mm, triquetrous to trigonous, smooth. Leaves: blade linear, up to 150 cm by 5–15 mm, long acute, flattish to plicate; sheath brownish purple or dusky brown. Involucral bracts 3–8, the longest up to 60 cm long. Inflorescence simple to compound, 15–40 by 15–40 cm; primary branches 4–10, 3–30 cm long; secondary branches 1.2–6 cm long, or spikes in sessile clusters. Spikes erect-patent to patent, cylindric, 3-6 by 1.5–3 cm; axis 3–5 cm long. Spikelets numerous, rather lax, spreading, linear, 6–20 by 1–1.5 mm, subterete; axis straight, winged. Glumes 9 or more on the longest spikelets, narrowly elliptic to elliptic, 1.8–2.2 by 1 mm, acute, apiculate, sides membranous, obscurely 1–2-nerved below keel, pale yellowish brown tinged with reddish brown, below keel, keel greenish or brown. Stamens 3; anthers 0.5 mm long, connective minute. Stigmas 3. Nutlets cylindric-ellipsoid to cylindric-obovoid, trigonous, 0.9–1 by 0.4–0.5 mm, yellowish brown, minutely punctate.
Thailand : NORTHERN: Chiang Mai (Doi Inthanon, Doi Pui), Chiang Rai, Phayao (Chun), Sukothai, Nakhon Sawan (Paknampo), Phitsanulok (Thung Salaeng Luang); NORTH-EASTERN: Khon Kaen (Ubonrat); EASTERN: Nakhon Ratchasima (Banchum Seng), Buri Ram; SOUTH-WESTERN: Kanchanaburi (Brangkasi, Hin Dat), Prachuap Khiri Khan (Bang Saphan); CENTRAL: Saraburi (Phu Khae), Ang Thong (Wat Tong Kung), Krung Thep Maha Nakhon (Bangkok); PENINSULAR: Surat Thani (Bangbao, Khao Raho), Nakhon Si Thammarat (Khao Chum Thong), Pattani, Narathiwat (Su-ngai Padi).
Distribution : Pantropical (India – type), extending north into S China and Taiwan.
Ecology : Swamps, bogs, river banks and rice fields, 0–800 m alt.
Vernacular : Kok dok daeng (กกดอกแดง), kok rang ka (กกรังกา), ya rangka (หญ้ารังกา)(Central).
Notes: This species is sometimes used for thatching. The spikelets have a distinct paler central band running the length of the spikelet which is seen particularly in dried material.