Which genus is native to western North America, Purshia or Bulbinella?
Purshia: Purshia (bitterbrush or cliff-rose) is a small genus of 5-8 species of flowering plants in the family Rosaceae, native to western North America, where they grow in dry climates from southeast British Columbia in Canada south throughout the western United States to northern Mexico. Bulbinella:  Other species are endemic to New Zealand, where they are most common in the central Otago region which enjoys a similar climate to the Cape Region of South Africa.
i don't know