This is a variable cosmopolitan weed of warmer regions (FNA 25). Most or all plants in Ky. are probably referable to ssp. brachiata (Steud.) P.M. Peterson & N. Snow, which is widespread in cropland and similar habitats from South America.to southern states, where it is considered partly adventive. The closely related ssp. mucronata (Michx.) P.M. Peterson & N. Snow has a more southwestern range within North America. There may be colls. of mucronata from BALL, CALL and MCRA by R. Athey (check EKY, MEM), from JEFF and MEAD by W. Thomas (check JEF), and from WARR by Pr (check MO), but those identifications have not been confirmed. See Peterson et al. (2012) for recent revision of Leptochloa sensu lato.