This occurs mostly in rocky open woods of east-central states, from Pa. and Va. to Iowa and Mo. In Ky. the only records are colls. of R. Athey from LIVI (EKY) and WARR (check MEM). Distinction from typical pycnocarpa deserves further study, since intermediate plants are known in Ill. and Ind. (FNA 7). [A record in SERNEC from BARR is based on misidentified Lepidium campestre.]