This globally rare grass occurs at several localities in the Ozarks of Mo., plus scattered disjunct sites in Ark., Ill., Ind., Ohio, Ky., Tenn. and Ala. (FNA 24, K, Y, W; M. Homoya, pers. comm.). It is often treatead as C. porteri ssp. insperata (Swallen) C.W. Greene, but there is little overlap in range with typical porteri. The two taxa do occur within 50 miles of each other in the Knobs of Ind., Ky. and Ohio, but with insperata generally on more xeric calcareous sites. In Ky., insperata has been verified only in ESTI and perhaps POWE; it was initially misidentified in ROWA (Campbell et el. 1992). No flowering has been observed in Ky., but comparison of vegetative material with authentic specimens from Ohio does support the identification. C. insperata is glabrous on the sheath collar (versus densely hairy); blades are light green and somewhat glaucous on both sides (versus darker green and less scabrid below); reported 2n = 56 (versus 84-104).