IMPERATA

Imperata Cirillo, Pl. Rar. Neap. 2: 26. 1792; Boiss., Fl. Or. 5: 542; 1884; Hook. f., Fl. Brit. Ind. 7: 106. 1897; Bor, Grasses Burma, Ceyl. Ind. Pak. 169. 1960; Sharma & Khosla, Grasses Punj. and Chandigarh 222. 1989; Chen & Phillips, Fl. China @ eFloras.org 22: 583.

Perennial, strongly rhizomatous. Culms erect, unbranched, few-noded. Leaves mostly basal; leaf blades linear to linear-lanceolate. Ligule membranous. Inflorescence a narrow, often spiciform silvery, silky panicle, branches bearing numerous very short racemes, racemes with tough rachis; rachis internodes and pedicels persistent, densely silky hairy. Spikelets paired, both pedicelled, small, delicate, +/- terete, enveloped in long silky hairs from callus and glumes; callus truncate, very small, pilose with long hairs, usually exceeding spikelets; 2- flowered, lower floret reduced to sterile hyaline lemma, upper floret bisexual. Glumes subequal, lanceolate, as long as spikelets, membranous, back long-pilose. Lower lemma shorter than glumes, hyaline, veinless. Upper lemma similar to lower lemma, apex obtuse, denticulate, ciliate, awnless. Palea short, broad. Lodicules absent. Stamens 1 or 2. Caryopsis small, oblong, free.

11 species

Imperata cylindrica

Imperata cylindrica (L.) Raeusch., Nomencl. Bot. Pl. Illustr., ed. 3: 10. 1797; Bor, Grasses Burma, Ceyl. Ind. Pak. 169. 1960; Dhaliwal & Sharma, Fl. Kullu Dist. 683. 1999; Kaur & Sharma, Fl. Sirmaur 675. 2004; Maheshwari, Illustr. Fl. Delhi f. 243.1960; Sharma & Khosla, Grasses Punj. and Chandigarh 222. 1989; Singh & Sharma, Fl. Chamba Dist. 793. 2006; Chen & Phillips, Fl. China @ eFloras.org 22: 584; Fl. Pak. @ eFloras.org p. 252; Lagurus cylindricus L., Syst. Nat. ed. 10: 878. 1759; Imperata arundinacea Cirillo, Pl. Rar. Neap. 2: 26. t. 11. 1792; Hook. f., Fl. Brit. Ind. 7: 106. 1897; Saccharum cylindricum (L.) Lam., Encycl. Meth. Bot. 1. 594. 1785.

Perennial with creeping rhizomatous root stock. Culms solitary or tufted, 25-70 cm high, 1.5-3 mm diameter, erect, unbranched, 1-4-noded, nodes glabrous or bearded; leaf blades flat, stiff, erect, 20-100 cm x 0.8-2 cm, linear to linear-lanceolate, ciliate at base, margin scabrid; leaf sheath glabrous; ligule a scarious erose rim, 1-2 mm. Panicles terminal, cylindrical, copiously silky hairy, 5-20 cm x 1.5-2 cm, branches short, binate, appressed, bearing numerous very short racemes. Spikelets paired, both pedicelled, small, 3-3.5 mm long, linear-lanceolate, acute, enveloped in long silky hairs from callus and glumes. Glumes nearly equal, as long as spikelet, lanceolate, membranous, acuminate, long silky hairs on back, hairs ca. 3 times length of glume, callus bearded with soft, white, 12-16 mm long silky hairs. Spikelets 2-flowered. Lower floret reduced to lemma (lower lemma), lemma ovate-lanceolate, 2/3 length of glumes, ciliate, acute or denticulate. Upper floret bisexual. Lemma (upper lemma) ovate, 1/2 length of glumes, denticulate, ciliate. Palea equal to upper lemma. Anthers 2, 2-3 mm long. Stigmas 2, plumose, purple.

Flowering and Fruiting: July to October
Common Names: Cogon Grass, Kunai Grass, Cotton Grass, Thatch Grass; Uloo, Sirhu, Khans (Hindi)

The studied taxon is Imperata cylindrical var. major with key characters:Leaf blades flat; spikelets 2.5-4.5 mm; anthers 2-3 mm long.