This native perennial grass is about 22½' 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.