Compilation
Panicum prostratum

Annual or subperennial (?), usually prostrate or creeping, throwing up secondary culms from the rooting nodes of the often long-decumbent base, the lower secondary culms frequently behaving like the primary, or sometimes the culms gathered into more contracted tufts, from 1/2 to 1 1/2 ft. high, internodes slender to very slender, numerous, those of the decumbent base frequently angular or compressed and bare, of the erect or ascending portions of the culms terete and except the uppermost more or less sheathed, all glabrous. Leaf-sheaths loose or the upper somewhat tight, quite glabrous and smooth except at the densely ciliate margins and frequently pubescent nodes, or occasionally sparingly hairy; ligules reduced to a shortly ciliate rim; blades lanceolate to ovate- or linear-lanceolate, 1/2–2 1/2 in. by 2 1/2–8 lin., rounded to subcordate at the base, attenuated from low down to an acute point, flat or wavy, frequently somewhat rigid, green, quite glabrous or more frequently ciliate downwards, with long stiff hairs or sometimes also pubescent or softly hirsute, margins cartilaginous, scabrid, midrib very slender, lateral nerves numerous, close, very fine, the primary hardly differentiated. Inflorescence at length usually long-exserted, ovate to obovate-oblong in outline, from 1 to over 3 in. long, of few to over 12 obliquely erect or spreading slender secund spiciform racemes; common axis slender, semiterete and adaxially channelled below, angular upwards, scaberulous along the angles. Racemes solitary, upwards gradually approximate or irregularly crowded into false whorls, 6–15 lin. long, sessile or subsessile, simple or subcomposite at the base with very short secondary racemes, 2- or irregularly pluriseriate, dense to somewhat loose; rhachis slender, slightly wavy, triquetrous, 1/7– 1/5 lin. wide, pubescent or villosulous at the base, scabrid along the angles, internodes 1/2–1 lin. long; pedicels paired (or the lower in clusters of 3), unequal, the longer up to 1/2 lin. long, slender, angular, the other very short to rudimentary, or solitary, usually with some long spreading white hairs and small discoid tips. Spikelets or their pairs or clusters subcontiguous or discontiguous or crowded downwards, elliptic-oblong, acute, up to 1 lin. long, glabrous or greyish-pubescent, greenish, rarely tinged with purple. Glumes very dissimilar; lower reduced to a small rounded or truncate and sometimes apiculate nerveless scale, 1/6– 1/5 lin. long, upper corresponding in size and outline to the spikelet, distinctly 7-nerved, glabrous or densely pubescent. Lower floret barren, with or without rudimentary stamens; valve very similar to the upper glume, 5-nerved; valvule oblong, subacute, shorter than the valve. Upper floret hermaphrodite, elliptic, pale, finely transversely rugulose, over 3/4 lin. long; valve with a minute mucro. Anthers 3/5 lin. long.