Threenerve Goldenrod (Solidago velutina DC.)

Also known as Solidago arizonica Wooton & Standl. (Misapplied).

Many authorities list Solidago arizonica Wooton & Standl. as a synonym of this species. However, taxonomic authorities such as POWO and WFO list that name as a synonym of Canada goldenrod (Solidago canadensis), reflecting the fact that the type specimen for that name is actually S. canadensis. However, the bulk of the use of the name S. arizonica, as well as the largely equivalent name S. arizonica var. canadensis, was misapplied to refer to this species. As such, most uses of that name in the literature refer to this species. This pecular scenario probably explains why POWO erroneously reports S. canadensis in the southwest even though they treat it separately from this species; their map reflects sources that report S. arizonica in the southwest, misapplying the name, and wrongly include them to the range of S. canadensis. Both POWO and BONAP have merged Solidago californica Nutt. into this species, but they disagree as to the details of the merge. BONAP merged most into ssp. californica, except var. nevadensis, which was merged into ssp. velutina. However, POWO, which recognizes 3 subspecies instead of BONAP's 2, instead merged that variety into ssp. sparsiflora, the subspecies not recognized by BONAP. This does not affect our species-level information but take note that information about subspecies may be inconsistent across different sources using the different treatments.