This grass is a summer annual about ½-1½' tall, forming a small tuft of leafy culms. These culms are erect to widely spreading and unbranched; they are light green to reddish green, terete, slender, and glabrous. There are 2-4 alternate leaves along the length of each culm; their blades are ascending to widely spreading. The leaf blades are 2-4' long and 3-5 mm. across; they are light green or grayish green, flat, and largely glabrous. The base of each blade is wider than the culm. At regular intervals along the margins of each blade, there are minute glandular droplets (may require 10x hand lens to see). The leaf sheaths are light green to dull purple and longitudinally veined; each sheath is slightly hairy above and glabrous below. At the junction of each sheath and blade, there is a conspicuous tuft of fine white hairs. Each culm terminates in a somewhat airy panicle of spikelets that is 1½-4' long and about one-half as much across; in outline, each panicle is narrowly pyramidal to ovoid. The central axis and lateral branches of each panicle are light green, slender, and glabrous. The lateral branches are widely spreading to ascending, dividing into short lateral branchlets that are divergent. At the tips of these branchlets, there are elongated spikelets about 4-10 mm. long and 1.5-2 mm. across. Immature spikelets are light grayish green to dark purple, while mature spikelets become light tan. Individual spikelets are narrowly oblongoid and flattened in shape, consisting of 5-18 florets and their overlapping lemmas (scales with florets) that are arranged in 2 columnar ranks. Each spikelet is slightly less wide at the top than the bottom. At the bottom of each spikelet, there is a pair of glumes (scales without florets). Individual glumes are about 1.5 mm. long, lanceolate in shape, glabrous, and folded along their keels; one glume is slightly longer than the other. Located above the glumes, the individual lemmas are 1.5-2.0 mm. in length. The lemmas are lanceolate-ovate in shape, glabrous, 3-veined, and folded along their keels. Hidden behind each lemma, there is a single floret and a membranous palea. The anthers of each floret are about 0.2 mm. long. The blooming period occurs from mid-summer to early fall. The florets are cross-pollinated by the wind. Fertile florets are replaced by tiny ovoid grains (up to 1 mm. long); the latter are small enough to be blown about by the wind. The shallow root system is fibrous. At favorable sites, this grass often forms colonies by reseeding itself.