Description: This native grass is a summer annual
about 1-3' tall that is usually tufted at the base, sending up multiple culms,
otherwise it is little-branched. The culms are green, terete, and nearly
hairless to hairy. The alternate leaves are more common toward the base of the
culms. Their blades are up to 10" long, 2/3" across, and rather floppy; they
are green and variably hairy, often becoming rather ragged in appearance with
age. The upper surface of each blade can be hairless to densely covered with
appressed
hairs, while the lower surface can have a few
scattered hairs along the central vein to densely covered with with long
spreading hairs. The leaf sheaths are light green to pale reddish green, finely
ribbed, and densely covered with long spreading hairs. Each culm terminates in
a strongly branched panicle of spikelets that is little-exerted from the
uppermost leaf. Immature panicles are funnel-shaped with a dense concentration
of branchlets and spikelets. Mature panicles are ovoid-globular and airy in
appearance from the widely spreading branchlets; they are up to 1½' long
and 1' across. Mature panicles often comprise one-half the length of the entire
plant. The central axis of the panicle is hairy, particularly at the swollen
nodes where the primary branchlets occur. The slender branchlets are rather
wiry, stiff, and mostly hairless. Each branchlet terminates in a single
spikelet. Each spikelet is about 2.0–2.5 mm. long, narrowly ovoid, and
hairless; it has a short beak at its apex. The scales of the spikelet consist
of a short glume, a long glume (that looks like a lemma), and a single lemma.
The short glume is about 1/3 the length of the spikelet, while the long glume
and lemma are the same length as the spikelet. The short glume is broadly
lanceolate; it often becomes pale purple, otherwise the scales of the spikelet
are light green. The blooming period occurs during late summer and early fall.
Shortly afterwards, the panicles and their spikelets become light tan. The
entire panicle can detach from the plant and roll across the ground, like a
tumbleweed, distributing the grains. Each spikelet produces a single grain
about 1.5 mm. long. The grains are ovoid and rather flattened, each one
tapering to a point at both ends. The root system is fibrous. This grass
spreads by reseeding itself. It often occurs as widely scattered plants in a
given habitat, or it may form dense colonies that are dominated by the airy
panicles.