Northeastern U.S., west to Minnesota, Iowa, and Missouri, south the Tennessee and n. Alabama, possibly North Carolina. Reported in Canada but specimens and images seem to be lacking. Disjunct in eastern Oklahoma and a large swath of central Texas; one report just across Rio Grande in Mexico. Range overlaps broadly in Northeast with Canadian Petrophila but seems not to overlap much if at all with Ozark Petrophila (MO, AR, OK) or Heppner's Petrophila (Texas Hill Country).
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