Digitaria sanguinalis, Scop.
Var. extensum.
This grass is an annual with stems ascending from a prostrate or geniculate, rooting branched base, greenish or purplish, glabrous and varying in length from 1 to 2-1/2 feet.
The leaf-sheath is thin, herbaceous, rather loose, keeled and glabrous. The ligule is a distinct membrane, truncate, rarely irregularly toothed. The nodes are glabrous.
The leaf-blade is linear-lanceolate, acuminate, flat when mature and convolute when young, glabrous, 1 to 12 inches long and 1/6 to 1/3 inch broad, the margin is very closely and finely serrate, the midrib is prominent with three or four main veins on each side.
The inflorescence consists of a few or many spikes, corymbosely arranged on a short angular slightly rough axis, erect or spreading, 1-1/2 to 4 inches long, the lowest ones in whorls of two to four; the rachis is nearly triquetrous, laterally winged, base thickened and with a few long white hairs; the peduncle is cylindric, smooth, 6 to 12 inches long.
Fig. 75.—Digitaria sanguinalis, Var. extensum.
1. A portion of spike; 2, 3 and 3a. the back and front views of a spikelet; 4, 5 and 6 the first, second and the third glume, respectively; 7. palea of the third glume; 8. anthers, lodicules and the ovary.