Paul M. Peterson, Stephan L. Hatch and Alan S. Weakley
Plants perennial; cespitose, not rhizomatous. Culms 30-80(90) cm. Sheaths dull and fibrous basally, glabrous or sparsely pilose below, hairs to 4 mm, contorted; ligules 0.1-0.3 mm; blades 7-31 cm long, 1.2-2.5 mm wide, flat to folded, glabrous abaxially, scabridulous adaxially, margins scabrous. Panicles 5-22(25) cm long, (0.6)1-11 cm wide, open to somewhat contracted, longer than wide, narrowly pyramidal, not diffuse; lower nodes with 1-2(3) branches; primary branches 0.6-8(11) cm, appressed or spreading to 70° from the rachis, not capillary, without spikelets on the lower 1/3; pedicels 0.8-6 mm, appressed, occasionally spreading. Spikelets 3-6 mm, plumbeous. Glumesunequal, lanceolate, membranous; lower glumes (1.2)1.8-4.5 mm; upper glumes 2.4-6 mm, at least 2/3 as long as the florets, occasionally 3-veined; lemmas (2.7)3-4.3 mm, ovate, membranous, glabrous, acute; paleas 3.1-4.5 mm, slightly longer than the lemmas, ovate, membranous, glabrous; anthers 1.7-3 mm, yellowish to purplish. Fruits1.4-2.1 mm, pyriform to globose, indurate, without a loose pericarp, smooth, shining, light brown. 2n = 72.
Sporobolus heterolepis grows at elevations of 40-2250 m, in lowland and upland prairies, along the borders of woods, roadsides, and swamps, and in north-facing swales. It is associated with many plant communities, and is also available commercially as an ornamental. It is restricted to the Flora region.