Culms 11-70 cm tall, usually simple; nodes usually hirsute. Sheaths hirsute, hairs papillose-based; Blades 3-16 mm wide, rounded basally. Panicles erect. Spikelets 1.9-3.3 mm. Lower paleas less than 1/2 as long as the upper florets. 2n = 18, 36 (for Panicum pampinosum).
Panicum hirticaule subsp. hirticaule is the most common of the subspecies, growing throughout the range of the species but occurring more often in arid habitats. Panicum alatum Zuloaga & Morrone has recently been described as a new species, differing from P. hirticaule subsp. hirticaule by the presence of paired elaiosomes at the base of a slightly stipitate upper floret. It is known from central Arizona, but apparently is more common in western Mexico.