E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

The name Boloria is derived from the Greek bolos (fishing net) and refers to the reticulate or checkerboard wing pattern (Emmet 1991). The common name "angled lesser fritillaries" refers to their small size and to the angled margin of the hindwing. The common name is used here for the first time.

Palearctic workers and their popular books restrict the use of the genus Boloria to that of Warren (1944) and use a second genus, Clossiana, for most species in this group. We accept that approach. As used by Palearctic authors, the genus Boloria is defined by the shape of the valves. The dorsal or superior dorsal process has two distinct and heavily chitinized projections (Shirôzu and Yamamoto 1953). The genus Clossiana has only one (Warren 1944). Grey (1989) further points out that the uncus of Boloria is heavily spiculate or covered with short, thick hairs. In addition, the hindwing margin has a characteristic sharp angle at the M₃ vein. Both Boloria and Clossiana have a bifid uncus, a tribal character. As defined by Palearctic workers, there are two to four species, only one of which occurs in North America.

The Mountain Fritillary occurs in mountains across the northern fourth of BC and south in the Rockies into AB. Its habitat is moist meadows, usually along streams at or near timberline.

The Mountain Fritillary is found throughout AK, along the north coast of YT and NT to the west coast of Hudson Bay. It ranges south through central and southern YT to the AB Rockies near Adams Lookout, Wilmore Wilderness Park. There are also disjunct populations in the Wind River Range of WY. The species is Holarctic, occurring from northern Europe to northeastern Siberia.