The new genus Trichanthecium (Poaceae, Paniceae) is proposed on the basis of shared morphological characters, including presence of membranous ligules, lax and open inflorescences, ellipsoid to obovoid and pilose or glabrous spikelets, the lower glume nearly 1/2 to as long as the spikelet and (1-) 3-nerved, the upper glume 3-5-nerved, and the upper anthecium indurate and covered with globose or elongated bicellular microhairs and simple papillae. This generic delimitation was confirmed with molecular phylogenetic studies utilizing analyses of chloroplast ndhF and rpoA sequences. Morphological characters and phylogenetic aspects of Panicum and other genera of Paniceae are discussed. Trichanthecium comprises 38 American and African species, which were previously assigned to Panicum sections Parvifolia and Verruculosa. Full synonymies and descriptions, and a key are provided; all species are mapped, and most are illustrated.