Specimens in existence of the presumably extinct legume Orbexilum stipulatum (T. & G.) Rydb. (=Psoralea stipulata T. & G.) were collected from 1835 to 1881. The species has been listed in various taxonomic works as having occurred in Indiana, Kentucky, and Ohio. However, after reviewing the evidence, it appears that O. stipulatum was endemic to Rock Island of the Falls of the Ohio River in Louisville, Kentucky, at the time of its discovery by botanists in the 1830’s.