Iseilema laxum, Hack.
It is a tufted perennial grass with a stout, short, creeping root-stock. Stems are slender, branched, ascending, 6 to 24 inches long.
The leaf-sheaths are somewhat loose, glabrous. The ligule is a shortly ciliate membrane.
The leaf-blade is linear, obtuse, glabrous and ciliate near the base, 2 to 6 inches long. The leaf-blades in the upper portions of the branches are smaller.
Fig. 167.—Iseilema laxum.
1. A cluster of spikelets with spathes. 2. a cluster consisting of the involucral spikelets and three inner spikelets; 3. the inner spikelets consisting of one sessile female or bisexual and 2-pedicelled male spikelets; 4, 5 and 6. the first, second and the third glume, respectively, of the involucral spikelet.
The inflorescence is a narrow long panicle bearing clusters of spikelets with spathes on slender peduncles, the outer spathes are narrow-lanceolate, glabrous or with a few hairs near the margin, 1/4 to 1 inch long; inner spathes are lanceolate, smaller with membranous margins. Each cluster consists of an involucel of 4 pedicelled spikelets forming a true whorl around 2 pedicelled and 1 sessile spikelets or 3 pedicelled and 2 sessile spikelets. The involucral spikelets are male, oblong-lanceolate, acute, with short flattened pedicels, bearded at the base, and have three glumes. The first glume is oblong-lanceolate, acute, 5- to 7-nerved and ciliate. The second glume is oblong-lanceolate, acuminate, equal or slightly shorter than the first, glabrous, 3-nerved and with infolded margins. The third glume is hyaline, linear, short, irregularly toothed at the apex. The inner pedicelled spikelets are similar to the involucral spikelets, but the third glume is very narrow, linear. The sessile spikelets are female, rarely bisexual, narrowly lanceolate, 1/5 inch long, glabrous and have four glumes. The first glume is lanceolate, chartaceous, truncate or 2-fid at the apex, faintly 5-nerved, with a few long hairs or glabrous, and with margins scaberulous towards the tip to about one-third the length of the glume. The second glume is lanceolate, acuminate, glabrous, sub-chartaceous, 3-nerved. The third glume is hyaline, nerveless, apex irregularly cut, short; sometimes this glume is wanting. The fourth glume is a very slender awn of about 1/2 inch.