NatureServe Conservation Status
Rounded Global Status Rank: G5 - Secure
Reasons: Plant widely distributed but local. Listed as nationally rare in USA by Crow (1982). Range is circumboreal; Labrador to Alaska, south to Maine, Michigan, New York, west into the Rockies, Arizona and California, also in Europe. Most often found in cool, mature cedar swamps or on slopes of mixed coniferous growth underlain by some type of calcareous bedrock. May be vulnerable to local reduction due to herbivory from overly abundant deer.