In Ky., this midwestern species of the tall-grass prairie is known only from a few old records: (1) C.S. Rafinesque (1836, 4:32 as Phaiosperma trifida), "discovered in 1823 in the Western glades of Kentucky"; (2) C.W. Short from CHRI (Perkins 1938); (4) Pr (addenda) from WARR; (5) a 1966 coll. from a roadside in TRIG (R.H. Ellis at APSC; Chester & Wofford 1992). P. nuttallii also occurs in some adjacent counties of Ill., Ind. and Tenn. Within southeastern states, the largest concentration is in or near the Black Belt of Miss. and Ala. (K).