Draba calcifuga (Brassicaceae), a new species from the Rocky Mountains of North America
Draba calcifuga Lesica (Brassicaceae) is an alpine species of the Rocky Mountains of Montana, Idaho, and Wyoming, U.S.A., restricted to noncalcareous soils. It has been confused with the sympatric D. oligosperma Hooker because both species are similar in habit, leaf size and shape, fruit size and shape, style length, and in the presence of doubly pectinate trichomes on the leaves. However, D. calcifuga has cilia and pectinate trichomes with crisped branches that do not occur in D. oligosperma. Draba calcifuga demonstrates low pollen stainability throughout its range, suggesting it is agamospermous. Although D. oligosperma is agamospermous over most of its range, it is sexual in its area of sympatry with D. calcifuga, suggesting that the latter may be derived from the former. Draba calcifuga is described and compared to four other species with doubly pectinate trichomes from the Rocky Mountain region.
Lesica, P. 2009. Draba calcifuga (Brassicaceae), a new species from the Rocky Mountains of North America. Novon, Vol. 19: 182-186.