This is a species of the Great Plains that extends east into e. Mo., c. Ill. and Ind., but it is perhaps only adventive along rights-of-way within more eastern states (D, Y). For Ky. there is only an obscure reference to T. scabra Raf. by Rafinesque (1836, 4:67): "Found by me 1823 in the glades near the mouth of the Tennessee R[iver]." T. scabra is considered to be a synonym of leptocarpa, according to Merrill (1949).