Stout goldenrod , verge d’or squarreuse
Solidago squarrosa Muhl. is native to the northeastern US and adjacent Canada. The species is distinguished by it cylindrical involucres with squarrose phyllaries (Semple & Cook 2006 FNA) and is one of the most easily recognized species in subsect. Squarrosae. The species is diploid 2n=18. Semple and Cook (2022) published cytogeography maps for S. squarrosa and related species.
The range shown below has some gaps that need confirmation, e.g. northern New York.
Solidago squarrosa was found to be one of the most distinct species in subsect. Squarrosae in a multivariate analysis including 14 species of the subsection focusing on the S. speciosa complex (Semple et al. 2017) and was strongly separated in a second analysis of just five species of subsection Squarrosae (Semple et al. 2017). Semple and Beck (2021) placed the species by itself in a very much reduced S. sect. Squarrosae; nearly all other species previously included in S. subsect. Squarrosae were placed in S. sect. Erectae.