Solidago sciaphila Steele is endemic to bluffs along the Mississippi R. in southern Minnesota and Wisconsin and northern Iowa and Illininois (Semple & Cook 2006 FNA). It can be similar to S. speciosa but has more serrate lower and mid stem leaves and is generally smaller to much smaller when growing in pockets of shallow soil on cliffs. Small plants are similar to S. hispida in general appearance. The species is the only tetraploid (2n=36) species in subsect. Squarrosae.
Semple et al. (2017) included S. sciaphila in a multivariate study of the S. bicolor complex along with S. hispida, S. porteri, and S. roanensis, and more broadly S. erecta. It was also compared to S. speciosa.