This annual or short-lived perennial (?) ranges widely from Central America to southeastern states, growing on wet soils of varied type. FNA 23 does not map the species in Ky., but does for all adjacent states except W.Va. S. reticularis Michx. is a distinct species on the Coastal Plain, but closely related. There is a coll. of C.W. Short (PH) that was determined as muehlenbergii by N.L. Britton, but it is labeled Ky. with no other data and might have come from another state.