Rank MethodLegacy Rank calculation - Excel v3.1x
Review Date2016-04-04
Change Date2016-04-04
Edition Date2016-04-04
Edition AuthorsBittman, R. L. (1987), rev L. Kutner (5/94), rev. Treher (2016)
Threat ImpactLow
Range Extent200,000 to >2,500,000 square km (about 80,000 to >1,000,000 square miles)
Number of Occurrences> 300
Rank ReasonsIn North America it is mainly a western species with isolated populations in West Virginia; it is found in Europe and Asia also (FNAEC, 1993). Based on herbarium records, the species appears to have many sites in Europe.
Range Extent CommentsSouthwestern South Dakota to Arizona and Texas and along the California Sierra Nevada to southwestern Oregon, with a disjunct population in West Virginia. Based on specimen records, this species appears to be common in Europe.