This is a widespread western, apogamous triploid (2n = 90), but it is virtually unknown east of the Mississippi Rv. except in s. Wis. and s. Ill. (FNA 2, K, W). The species has been found at one site on dolomitic limestone cliffs along Cedar Creek in BULL (KNK) during the 1950s (Reed 1952), 1970s (Cranfill 1980) and 1980s (M). It was relocated and mapped in 1993 by KSNPC staff. There are also isolated records from N.Car. and Va. (W).