1. Bouteloua curtipendula (Michx.) Torr. var. curtipendula (sideoats grama)

Pl. 141 h–j; Map 572

Plants with creeping rhizomes, forming few‑stemmed clumps. Flowering stems 30–100 cm long, erect or sometimes somewhat arched toward the tip. Leaf sheaths glabrous or the lowermost sparsely hairy. Leaf blades 5–35 cm long, (2)3–7 mm wide, flat, glabrous except sparsely pubescent on the margins near the base with short, pustular‑based hairs. Inflorescence elongate, linear, with (10–)30–70 spikes, these spreading to angled downward, shed intact as a unit, leaving the main axis of the inflorescence naked after the spikelets have been shed. Spikes 8–15(–20) mm long, with 2–8 spikelets, the axis of the spike not extended past the uppermost spikelet. Lower glume 3–4 mm long, linear or awnlike, glabrous or roughened. Upper glume 4.0–7.5 mm long, narrowly lanceolate, glabrous or roughened. Fertile lemma 3–7 mm long, lanceolate, glabrous or roughened, the central nerve extended into a short awn to 1 mm long at the tip. Sterile lemma sometimes reduced to short awns or more commonly with the body 0.5–3.5 mm long, the central nerve extended into an awn 1.5–5.0 mm long, the lateral nerves usually also extended into short awns. Anthers 1.5–3.0 mm long, reddish orange to orange, rarely yellow or purple. Fruits 3.4–3.8 mm long. 2n=20–103, mostly 2n=40. July–September.

Scattered to common nearly throughout Missouri, but absent from the Mississippi Lowlands Division (U.S. and adjacent Canada and Mexico). Glades, upland prairies, savannas, and rocky openings of mesic to dry upland forests, almost always on calcareous substrates; also roadsides and railroads.

Two other varieties occur in the southwestern United States and Latin America and differ in characters of their rhizomes (or lack thereof) and whether the stems are erect to ascending or more spreading and rooting at the lower nodes. Sideoats grama is one of the most important and widespread range grasses in the Great Plains and is considered an excellent native forage species.