189. Imperata Cirillo, Pl. Rar. Neapol. 2: 26. 1792.
白茅属 bai mao shu
Authors: Shou-liang Chen & Sylvia M. Phillips
Perennials, strongly rhizomatous. Culms erect, unbranched. Leaf blades mainly basal, linear, flat or rolled; ligule membranous. Inflorescence a terminal, silky-white, spikelike panicle, branches bearing numerous very short racemes; racemes with tough rachis, spikelets of a pair both pedicelled with one pedicel longer than the other, deciduous at maturity within a plumose involucre of hairs; rachis internodes and pedicels persistent, densely silky hairy, tips expanded. Spikelets small, delicate, ± terete, enveloped in hairs; callus very small, pilose with long hairs usually exceeding the spikelet; glumes subqual, lanceolate, membranous or lower glume herbaceous, back long-pilose; lower floret reduced to an empty hyaline veinless lemma, shorter than spikelet; upper lemma similar to lower, apex obtuse, denticulate, ciliate, awnless; palea short, broad. Lodicules absent. Stamens 1 or 2. x = 10.
About ten species: throughout the tropics, extending to warm-temperate regions; three species (one endemic) in China.
Imperata conferta (Presl) Ohwi has been reported in the literature from Taiwan, but its presence has not been confirmed. It is native to Indochina, Indonesia, and the Philippines. Distinguishing characters are given in the key below.