THAI FOREST BULLETIN (BOTANY) 36
Perennial loosely tufted with short rhizomes or fusiform tuberoid roots. Culms erect or weakly geniculate at base, 40–80 cm tall, smooth, glabrous, clothed at base with 2 to 4 pale-brownish cataphylls. Leaf-sheaths 6–12 cm long, usually longer than the internode, mid-nerve prominent, pale green, glabrous or pubescent on lower part and margins. Ligules membranous, 0.5–0.7 mm long, truncate, ciliolate at the margins. Leaf-blades 8–25 by 1.5–5 cm, ovate-lanceolate, pseudo-petiole, 5–12 mm long, chartaceous, glabrous, with prominent cross nerves, light green, base round gradually tapering above to a short-acuminate apex. Inflorescence a loose panicle, 15–30 by 6–10 cm, elliptic in outline, of narrowly racemose branches, 10–20 cm long. Spikelets 7–10 by 1.2–1.5 mm, bottle-shaped or ovate-lanceolate in outline, erect-patent, lanceolate, weakly laterally flattened, greenish, glabrous or sparsely haired, bearing 1 fertile and 3–7 sterile florets; pedicels short, 0.5–1 mm, with a tuft of hairs at the tip. Lower glume oblong, 3–3.5 mm long, 5-nerved, with a few cross-nerves, coriaceous, glabrous or pilose margin membranous, apex emucronate. Upper glume oblong, 4.7–5 mm long, 7-nerved, apex obtuse. Lower floret bisexual. Lower lemma oblong, 7–7.5 mm long, 7- nerved, chartaceous, apex with a retrorsely scabrid awn, margins ciliolate towards apex. Palea as long as the lemma, membranous, 2-keeled; keel narrowly winged above the middle part. Lodicules 2, cuneate. Ovary ovoid; stigmas plumose yellow or dark purple. Stamens 2. Upper florets reduced and sterile. Upper lemmas successively clasping, the awns, 1–1.5 mm long, retrorsly scabrid, forming a small tuft.
Thailand.— NORTHEASTERN: Loei [Phu Luang Wildlife Sanctuary, 29 Aug. 1968, Bunchuai 1732 (K); Phu Luang Wildlife Sanctuary, 16 Nov. 1968, Chermsiriwatthana 1110 (BK); Phu Kradueng, 13 Sept. 1990, Chantaranothai et al. 90/194 (K)]; Nong Khai [Phon Pisai, 19 Nov. 1963, Pradit 716 (BK)]; EASTERN: Chaiyaphum [Chulaporn Dam, 5Aug. 1972, Larsen 31465 (K)]; Nakhon Ratchasima [Katok, 30 Dec. 1923, Kerr 8167 (BK); Lat Bao Khao, 7 Nov. 1931, Put 4318 (K); KhaoYai National Park, 30 Oct. 1970, Larsen 4274 (K); 22 Oct. 1971, van Beusekom et al. 3863 (K); KhaoYai National Park, 12Aug 1974, Maxwell 74– 802 (BK)]; SOUTHEASTERN: Prachin Buri, Arun Pratet, 17 Oct. 1928, Put 1990 (BK, K)]; Chon Buri [Khao Khieo, 20 July 1963, Larsen 10662 (K); Khao Khieo, Sriracha, 29 Aug. 1976, Maxwell 76–623 (BK)]; Chanthaburi [Chanthaburi, 20 Dec. 1924, Kerr 9722 (BK, K)]; Trat [Ko Chang, 26 Sept. 1924, Kerr 9191 (BK); PENINSULAR: Ranong [Khao Pawta Luang Kaeo, 2 Feb. 1929, Kerr 16964 (BK, K)]; Surat Thani [Kanchanadit, 1Aug. 1927, Kerr 13097 (BK, K)]; Nakhon Si Thammarat [Lan Saka, 18 May 1971, Sadakorn 253 (BK)]; Trang [Khao Soi Dao, 28April 1930, Kerr 19178 (BK, K); Thale Song Hong, 27 Jan. 1958, SØrensen et al. 736 (K)]; Satun [Kuan Kalong, 15 Oct. 1970, Charoenphol et al. 3288 (K)]; Songkhla [Khao Khieo, 27 July 1918, Kerr 16005 (K)]; Narathiwat [Bacho district, 18 Dec. 1968, Sangkhachand 1584 (BK); Tak Bai, Ku Chum, 14 Sept. 1987, Niyomdham & Sriboonma 1603 (K)].
Distribution.— India, Sri Lanka, China, Japan, Myanmar, Indo-China and Malesia. Ecology.— Shady understory of dry evergreen and bamboo forests and river bank. Use.— This species is used as a fodder plant.
Vernacular.— Phai pen lek (ÅnÁ }Á®¨È) (Trang); ai lek mai phai (Å°oÁ®¨ÈÅ¤oÅn), ya phai (®oµÅn) (Peninsular); ya khui mai phai (®oµ»¥Å¤oÅn).
Note.— L. gracile is a remarkable grass with one fertile and several sterile florets which are prominent with tufted, retrorsely scabrid awns that serve as dispersal agents.