Myriogenospora atramentosa produces partial to complete sterility of host grasses. Geographical and host species distributions were assessed and updated. It is reported only from the New World and appears to be limited to the highly evolved grass tribes Andropogoneae and Paniceae. Included in these tribes are the previously unreported host species Panicum scoparium, Paspalum urvillei, Erianthus brevibarbis, E. contortus, E. giganteus, and hybrids from crosses with Erianthus spp. Additionally, M. atramentosa is reported for the first time growing on Paspalum notatum (bahiagrass), and Panicum hemitomon in South Carolina, U.S.A. Sequence data (ITS regions 1 and 2 and 5·8S rDNA) from several isolates indicated that there is a significant level of DNA sequence differentiation between isolates of M. atramentosa, which suggests that there are at least two distinct sequence groups, or cryptic species, within the currently defined morphological species.