Cirsium undulatum is widely distributed in the wstern half of North America from the dry plains and plateaus of the Pacific Northwest eastward across the Great Plains to Manitoba and the Dakotas and south to Texas, New Mexico, and northwestern Mexico. (swbiodiversity.org)
Cirsium undulatum is known to hybridize with C. flodmanii, C. hookerianum , and C. scariosum var. (swbiodiversity.org)
Widely distributed1
Cirsium scariosum is a widely distributed complex of intergrading races distributed from southwestern Canada to northwestern Mexico. (swbiodiversity.org)
PLANTS2
Unlike many other Tephritidae, even species in Europe that use Cirsium capitula like Urophora solstitialis, P. gentilis does not cause host plants to form galls or host-tissue growth. (wikipedia.org)
Within a given year, two generations of Paracantha gentilis adults appear at Cirsium plants. (wikipedia.org)
Species3
F. Petrak (1917) recognized ten species plus several subspecies for the taxa I am treating here as C. scariosum (in the broad sense). (swbiodiversity.org)
The latter two species, while clearly related to C. scariosum , have a range restricted mostly to Canada. (swbiodiversity.org)
Cronquist (1994) treated C. scariosum as an extremely variable species that included the four species recognized by Moore and Frankton plus the variety proposed by Welsh. (swbiodiversity.org)
Flora of Nort2
The name of Cirsium foliosum was misapplied to many plants in the western U.S. (Keil in Flora of North America 2006). (mt.gov)
Many specimens have been annotated to Cirsium scariosum which is a highly variable (polymorphic) species (Keil in Flora of North America 2006). (mt.gov)
Plants2
Cirsium foliosum was included in the Flora of Montana (Booth 1966) which was the basis for its report in the Vascular Plants of Montana (Dorn 1984). (mt.gov)
Within a given year, two generations of Paracantha gentilis adults appear at Cirsium plants. (wikipedia.org)