Urochloa fusca (common name: browntop signalgrass) is a wild grass species with a native native range extending from Paraguay in South America to the southern United States (Alabama, Arizona, Florida, Georgia, New Mexico, Texas, and Oklahoma), and it is now found as a weed in Australia. The species is diploid, with a base chromosome number of 9, and utilizes the PCK enzymatic subtype of C4 photosynthesis. Based on a molecular phylogeny of the genus Urochloa, the closest relatives of U.