Panicum arundinariae Trin. ex E. Fourn.

Panicum virgultorum Hack. Oesterr. Bot. Zeits. 51: 369. 1901
Plants perennial, ascending from a decumbent or sometimes a widely creeping base, branching and rooting at the lower, geniculate nodes; culms slender, wiry, 0.4^1 meter or more long, compressed, glabrous, or pubescent below the nodes; nodes pubescent or glabrous; leafsheaths often as long as the internodes, usually short-ciliate, otherwise glabrous or the lowermost pubescent; ligule membranaceous; blades 5-10 cm. long, 5-10 mm. wide, narrowly lanceolate, acuminate, narrowed to the base, scabrous on the upper surface, smooth and glossy beneath; panicles mostly long-exserted, 2.5-7 cm. long, half to two thirds as wide, the 2-4 branches ascending, compactly flowered except at the base, or the lower sometimes naked one third its length, the short branchlets and pedicels pubescent; spikelets 1.6 mm. long, 0.9 mm. wide ; first glume less than one fourth the length of the spikelet ; second glume and sterile lemma equal, 5-nerved; fruit 1.5 mm. long, 0.8 mm. wide, oval, smooth and shining but with sparse, long, appressed, silky hairs.
Type locality: Near Alajuelito, Costa Rica. Distribution: Southern Mexico to Panama.