Panicum fauriei var. carteri is a low, tufted annual grass that is 2 to 30 cm (0.8 to 11.8 in) tall. The stem, leaf, and inflorescence morphology are uniform in the Panicum fauriei complex, which includes two additional varieties; P. fauriei var. fauriei and P. fauriei var. latius. The aerial stems are usually branched and puberulent. The leaves are attached to the stem above the ground. The blades are 1.5 to 12 cm (0.6 to 4.8 in) long and 0.1 to 0.4 cm (0.04 to 0.2 inches) wide, loosely involute, upper surface pilose (long hairs), lower surface puberulent (short hairs). The flowers are arranged in a tightly branched inflorescence which is 1 to 11 cm (0.4 to 4.3 in) long. The axis and branches of the inflorescence are puberulent to sparsely pilose (short to longer hairs). The recognition of three varieties is based on spikelet morphology, particularly glume length and pubescence. The spikelets in P. fauriei var. carteri are 1.8 to 2.3 mm (0.07 to 0.09 in) long, acute, and shortly pubescent. In P. fauriei var. fauriei the spikelets are 1.5 to 2.3 mm (0.06 to 0.09 in) long, usually acute and glabrous. In P. fauriei var. latius the spikelets are 2 to 4.2 mm (0.08 to 1.7 in) long, acuminate to acute, short pubescent with short to long tufts of hair at the apex of the glumes.