Plants similar to subsp. rigidulum, but more conspicuously purple-tinged throughout, especially the panicles. Ligules0.3-1 mm, membranous; blades usually 5-12 mm wide, flat, mostly glabrous or scabridulous, bases about equal in width to the subtending sheaths. Panicles relatively narrow; branches few, stiffly ascending. Spikelets 2.4-3 mm long, usually less than 0.6 mm wide, conspicuously stipitate, purple, often falcate, subsecund along the branchlets. Upper florets stipitate, stipes to 0.4 mm, slender.
Panicum rigidulum subsp. elongatum is most common in the piedmont and mountain regions of the eastern United States