Panicum rigidulum Nees
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Coarse, densely tufted perennial to 1.5 m; lvs mostly crowded toward the base; sheaths glabrous, strongly compressed; ligule short, membranous, erose; blades narrow, 2–4 dm, sometimes exceeding the panicle, scaberulous on the margin; panicle 1–3 dm, pyramidal or narrow, its branches scabrous; spikelets lance-ovoid, green to purple, 1.8–3 mm, on pedicels half to twice as long; glumes and sterile lemma shortly to long-acuminate, sharply veined and somewhat keeled; first glume half to two-thirds as long as the spikelet; second glume and sterile lemma subequal, conspicuously longer than the often shortly stipitate fr; 2n=18. Wet soil; Me. to Mich., s. to Fla. and Tex. (P. agrostoides; P. condensum; P. stipitatum)