The recognition here of our local member of the cut-leaf balsamroots (subgenus Balsamorhiza) as Balsamorhiza hispidula, rather than B. hookeri var. hispidula, follows Weber’s (2006) treatment of the genus in Flora of North America, which is also followed by the current volume of Flora of the Pacific Northwest.  Independent of whether treated as species or varieties, the distinction between hispidula and hookeri is subtle, with hispidula having leaves that are brighter green, somewhat broader, and a bit larger on average, with broader lobes.  Following Weber’s treatment, true Hooker’s balsamroot (B. hookeri) does not occur in Idaho, although this has been the name most commonly used for our plants in previous treatments.

In the greater Boise Front, hairy balsamroot is evidently restricted to the Oregon Trail and South Boise subunits, reflecting the geological differences on the south side of the Boise River.  Hybrids with arrowleaf balsamroot can be found in sites where the two species co-occur, such as the Oregon Trail Recreation Area, even though hairy balsamroot tends to bloom earlier than arrowleaf balsamroot.  Hybrids are generally larger than the low-growing hairy balsamroot, with leaves intermediate between the two species.

Bernice Bjornson had this to say about this species (as B. hirsuta):  “Balsamorhiza hirsuta is rough hairy. Its compound leaves arching gracefully from the short stem make one think while he is at some distance from the plant that here is a fern growing in the desert.  Closer examination corrects the first impression, for the leaves, though much cut, do not grow like fern leaves, and the yellow flowers immediately proclaim the plant not to be a fern.”

Weber, William A.  2006.  Balsamorhiza.  Flora of North America 21: 93–99.