e-Flora of Thailand

Volume 6 > Part 4 > Year 1998 > Page 359 > Cyperaceae > Cyperus

16. Cyperus malaccensis Lam.wfo-0000377477

Tabl. Enc. 1: 146. 1791; C.B.Clarke in Hook.f., Fl. Br. Ind. 6: 608. 1893; Camus in Fl. Gén. I.-C. 7: 63. 1912; Ridl., Fl. Malay Penins. 5: 147. 1925; Kük, in Engl., Pflanzenr. 4(20), 101 Heft: 86. 1935; J.Kern, Reinwardtia 6: 55. 1961; in Fl. Males., Ser. 1, Spermat. 7: 613, f. 53. 1974; Raymond, Dansk Bot. Ark. 23: 346. 1966; Hô, Câyco Viêtnam III. 2: 675. 1993. 360


Accepted Name : This is currently accepted.


Description : Rhizomatous perennial; rhizome long-creeping. Culms 1-few, 60–180 cm by 7–12(–15) mm, smooth, sharply triquetrous. Leaves reduced to bladeless sheaths except for upper 1–3 leaves; blade linear, linear-lanceolate, 5–25 cm by 3–16 mm, acute or shortly acuminate, ± flattened; sheath 8–20 cm long, greenish to reddish brown. Involucral bracts 3–4, the longest up to 30 cm by 8–15 mm. Inflorescence simple to compound, somewhat congested, subglobose, 2–10 by 4–15 cm; primary branches 3–8, unequal, 3–10 cm long; secondary branches 0.3–1.6 cm long. Spikes ovoid, 1–2.5 cm long; axis 0.2–1 cm long, smooth, glabrous. Spikelets 2–15 per spike, linear, 10–13 by 1.2–1.8 mm, subterete; axis straight. Glumes 9 or more on the longest spikelets, elliptic to ovate, 2–2.2 by 1–1.5 mm, obtuse, sides chartaceous, indistinctly 5–7-nerved around keel, glaucous and tinged or flecked with brown or dark reddish, the margins widely pale membranous, keel rounded, brownish. Stamens 3; anthers 0.8–1 mm long. Stigmas 3. Nutlets cylindric, trigonous, 1.7–2 by 0.5 mm, blackish brown, minutely punctate.


Thailand : CENTRAL: Krung Thep Maha Nakhon (Bangkok), Samut Prakan (Ban Bang Pu Kao); SOUTH-EASTERN: Chanthaburi; PENINSULAR: Ranong (Nam Chut), Surat Thani (Pak Nam), Satun.


Distribution : Middle East to India, Indochina and S China. Also Malesia (Malay Peninsula – type) to N Australia and Polynesia.


Ecology : Marshy places near brackish or salt water.


Vernacular : Ya sam liam (หญ้าสามเหลี่ยม)(Central).


Notes: A rather large species with a stout rhizome which occurs near brackish or salt water. It is closely related to the following species but has a glabrous spike axis up to 1.3 cm long.


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