Description: This native perennial grass is about
2–2½' tall and unbranched. The culms are light green, glabrous, and
terete (round in cross-section); later during the fall, they become light tan.
The alternate leaves are more common toward the base of each culm. The leaf
blades are up to 8" long and ¼" across; they are light green to green,
mostly hairless, and rough along their margins. However, toward the base of
each leaf blade, there is often a few white hairs that are somewhat deciduous.
The larger leaf blades often have prominent central veins. The leaf sheaths
are light green, finely ribbed, and hairless. Each ligule has a ring of short
fine hairs. The nodes are slightly swollen, rough, and often reddish or
brownish green; the portion of the culm near each node may be tinted similarly
as well. The culm terminates in a narrow raceme up to 10" long that consists of
30-50 pendulous spikes. Each spike is about ½" long and consists of
about 5 spikelets. Each spikelet consists of a pair of linear-lanceolate glumes
and a pair of linear-lanceolate lemmas; only one of the lemmas is fertile. The
spikelets are up to 1/3" long and greenish red while the flowers are blooming,
but they later become tan. Each glume tapers into an acute tip, while the tip
of each lemma is often notched on either side. The anthers of the fertile
lemmas are bright red to brownish red, while their stigmas are white and
feathery. The blooming period occurs from mid-summer to early fall. The spikes
of the inflorescence persist into the fall, after which they fall to the ground
in their entirety (the glumes are non-persistent). Each fertile lemma bears a
single grain. The root system has fibrous roots and short rhizomes. Side Oats
Grama often forms tight bunches of culms from its rhizomes, although it also
occurs as scattered plants. In moist areas where there is little competition,
it may form a dense sod.