These are erect perennial grasses. The inflorescence is a spike-like panicle, with very short filiform inarticulate branches and rachises. Spikelets are binate, 1-flowered, all alike, both pedicelled, articulate at the base and hidden by the very long silky hairs arising from a small callus and from the glumes. There are four glumes. The first two glumes are membranous, lanceolate, and subequal. The third glume is shorter and smaller, hyaline. The fourth glume is still smaller and hyaline. Stamens are two, rarely one. Lodicules are not found. Styles connate below, with stigmas very long, narrow and exserted at the top of the spikelets. Grain is small and oblong.
Imperata arundinacea, Cyril.
This is an erect perennial grass with creeping, stoloniferous root-stocks, with aerial stems varying from 6 inches to 3 feet.
The leaf-sheath is loose and glabrous. The ligule consists of long soft hairs. The nodes are naked or bearded.
The leaf-blade is linear, flat, tapering from about the middle towards the top, finely acuminate, and also narrowing towards the base into the stout midrib, margins with fine long hairs at the base, 6 to 18 inches by 1/10 to 1/3 inch, scabrous above and smooth beneath.
The panicle is narrow, spike-like, silvery, 3 to 8 inches; branches are short and appressed and the internodes of spikes are short with the tips dilated.
The spikelets are 1/8 to 1/6 inch concealed by long silvery hairs of the callus and the glumes, articulate at the base; callus hairs are about twice as long as the spikelet or longer.
There are four glumes in the spikelet. The first glume is ovate-lanceolate, obtuse, with ciliate tips and long hairs at the back below the middle, rather thickened towards the base, dorsally hairy, 3- to 7-nerved, nerves not reaching the tip. The second glume is as long as the first, with membranous margins and with long hairs at the back, 3- to 7-nerved. The third glume is hyaline, less than half as long as the first and second glumes, oblong, obtuse or irregularly toothed, nerveless or 1-nerved. The fourth glume is slightly shorter and narrower than the third, ovate, acute, obtuse or toothed, ciliate, nerveless or faintly 1-nerved, paleate; palea is about half as long as the glume, quadrate, toothed or retuse, nerveless, glabrous. There are only two stamens with orange anthers. Styles are slender, long, with purple stigmas. Lodicules are absent. Grain is small and oblong.