Distribution.—Throughout India—westward to tropical Africa.
29. Anthistiria, L. f.
(Themeda, Forsk.)
These are tall grasses, annual or perennial. Leaves are usually long and narrow. The inflorescence consists of racemes or panicles of fascicled spikes in the axils of spathiform bracts. The spikelets vary in number from six to eleven in a cluster, the four lowest being male or neuter, and forming an involucre with whorled or superposed pairs round either 1-sessile bisexual spikelet with two pedicelled spikelets or two superposed bisexual, the lower with one pedicelled, the upper with two.
The involucral spikelets are male or neuter, the largest, and consist of three glumes. The first glume is oblong, lanceolate, dorsally flattened, many-nerved, margins narrowly incurved and keels narrowly winged. The second glume is membranous, lanceolate, acute, 3-nerved, with ciliate margins. The third glume is hyaline, smaller than the second, 1-nerved or this glume may be absent, stamens have large anthers. The pedicelled spikelets are similar to the involucral in every respect but smaller, male or neuter, but the first glume is not winged on the keels. The bisexual (or female) spikelets are smaller than the involucrant spikelets, linear-oblong, subterete, obtuse with a rigidly bearded callus. There are four glumes in the spikelet. The first glume is terete, or dorsally compressed or channelled, coriaceous and at length hardened, margins incurved, dark brown to almost black when old. The second glume is as long as the first, linear, dorsally chartaceous, with broadly incurved membranous margins, 3-nerved. The third glume is very small, hyaline, 1-nerved, epaleate. The fourth glume is the flattened base of the awn, epaleate. The lodicules are two, cuneate. Anthers are rather small. Styles are laterally or terminally exserted. Grain is narrow, obovoid, biconvex, with two grooves on the anterior side and with a long embryo.
Anthistiria tremula, Nees.
This is an annual or perennial. Stems are stout or slender, erect or ascending from a creeping root-stock, simple or branched, 1 to 4 feet.
The leaf-sheath is smooth, compressed. The ligule is a narrow membrane.