This is a widespread perennial (although often short-lived or even biennial), centered in east-central states, but rare to absent on the southeastern Coastal Plain (K). It has been divided into eastern (typical) and western varieties The latter (var. ludoviciana DC.) is indistinct in Mo. (Y), but it might be looked for in w. Ky. The white-flowered form has been found in FAYE (C. Chandler, pers. comm.) and WOOD (E. Carr, pers. comm.).