Sagebrush bluebells is seldom encountered in the Boise Front area, currently known only from a few scattered localities at higher elevations, mostly within the Conifer Zone.  It differs from the slightly more common longflower bluebell (Mertensia longiflora) in having the corolla tube only slightly longer than the flared limb (vs. nearly twice as long), somewhat larger and more numerous stems (at least on average), which arise from a sturdier rootstock (vs. a tuberous-thickened easily detached root).

Mertensia foliosa has previously been included in a more inclusive M. oblongifolia, which is the name that this plant would be treated as in existing wildflower guides.  However, recent phylogenetic work (e.g., Nazaire et al. 2014) has resulted in restricting the name M. oblongifolia to a species endemic to Montana, as indicated in the Flora of the Pacific Northwest (second edition).

Nazaire, M., X.-Q. Wang, and L. Hufford.  2014.  Geographic origins and patterns of radiation of Mertensia (Boraginaceae).  American Journal of Botany 101: 104-118.