This occurs in most eastern states, but it is concentrated in the central and lower Mississippi Valley, and rare to absent in most southeastern states (K). In Ky. and Tenn. it appears to be a conservative remnant of taller native grassland on or near the Pennyrhile Karst Plain and on uplands of the Mississippi Embayment. It is typical of somewhat cherty or sandy soils, not purely calcareous glades. As noted by Isely (1990), the species is "relatively monomorphic"; see further notes under obtusum.