Culms densely tufted, 1-4 dm, ±erect to spreading or ascending from a geniculate base and becoming prostrate; pubescence on at least some of the sheaths and internodes bistratal as in nos. 21-23 [Panicum commonsianum Ashe; Panicum lancearium Trin.; & Panicum columbianum Scribn.], with intermingled short, crisp hairs and much longer, coarser, straighter ones, the lower internodes and sheaths evidently hairy, the upper often progressively less so; ligule a band of hairs 0.5-4 mm; blades erect or ascending, 2-6 cm נ2-5 mm, short-hairy on both sides; primary panicle ovoid, 2-5 cm, its axis puberulent to glabrate, with widely spreading branches; spikelets finely hairy, oblong-ovoid, 1.3-1.6 mm; first glume subrotund to triangular-ovate, a fourth to two-fifths as long; autumnal plants prostrate to erect, with numerous branches from all nodes, tending to form large mats, the blades slightly to evidently reduced, the infls varying from clusters of spikelets hidden among the lvs to exsert panicles 1-2 cm; 2n=18. (P. albemarlense; P. auburne; P. meridionale) Perhaps properly to be subordinated to P. acuminatum Sw.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.