This is a variable species across central and eastern North America, typical of base-rich outcrops in several disjunct regions, but rare to absent in southeastern states (K). Typical michauxii occurs from northeastern regions to Ark., Mo., n. Ill., n. Ind., s. Ohio, e. W.Va., w. Va. c, Tenn., perhaps Ala. (W) and perhaps S.C. (F). For Ky., there is only an old coll. of C.W. Short (PH) from "wet rocky places", and presumed by M to come from near Hopkinsville (CHRI); and a recent coll. has been reported from nearby SIMP (EKY) There is also an unverifiable sight record from Grape Knob in POWE (M). Whilst somewhat tenuous, occurrence of this species in Ky. was also accepted by F, FNA 5 and W. S. michauxii differs from the patula complex as follows (W): plants perennial from woody crowns (versus annual); leaves rigid, with axillary fascicles (versus flexuous, without axillary fascicles); pedicels glabrous (versus sparsely to densely stipitate-glandular).