Fig. 160.—Andropogon annulatus.
1. Full plant; 2. base of the leaf and ligule.
Andropogon annulatus, Forsk.
This is a densely tufted perennial grass.
The main stem is underground, rhizomiferous, and covered with scale leaves; branches are many arising in tufts, leafy, procumbent at base and afterwards geniculately ascending and ending in inflorescence, occasionally rooting at the nodes and varying in length from 2 to 3 feet. The internodes vary from 1-1/2 to 4 inches, pale or purplish, slightly flattened, smooth and glabrous.
The leaf-sheath is terete, glabrous, shining, green or purplish, closed, with margins where separate ciliated and profusely so at the tip especially the outer or both. The ligule is membranous truncate, glabrous, about 1/16 inch in height. Nodes are purple and softly villous.
Fig. 161.—Andropogon annulatus.
1. Front and back views of a portion of the spike; 2. a sessile and a pedicelled spikelet; 3, 4, 5 and 6. the first, second, third and the fourth glume, respectively, of the sessile spikelet; 7. the ovary, stamens and lodicules; 8, 9 and 10. the glumes of the pedicelled spikelet.
The leaf-blade is linear-lanceolate, acuminate, scabrid, sparsely hairy, becoming glabrous except at the base and with tubercle-based hairs on the upper surface.