Distribution, Habitat Affinities, and Conservation of Prairie Moonwort (Botrychium campestre) on Its Northern Range Limit

Prairie moonwort (Botrychium campestre W.H. Wagner & D.R. Farrar) from the adder's tongue family (Ophioglossaceae) is a rare plant species in North America with a NatureServe designation of G3N2 (Globally Vulnerable, Nationally Imperiled). The species reaches its northern distribution limit in Saskatchewan, Canada. The range of B. campestre is described here from literature, herbarium data, and field studies. Two newly discovered peripheral populations are reported, and their habitats are characterized in detail. One of the new occurrences was monitored over a multiyear period, and changes in population and vegetation cover are described. Possible threats to the newest occurrences are identified. These results constitute the first reference on the status of B. campestre in Saskatchewan, which is important for the management and conservation of this rare plant species. Recommendations to protect these populations and to establish monitoring to track changes in their natural habitat are presented.