Showy Goldenrod
Solidago speciosa Nutt. is treated in a narrow sense here based on research done in the Astereae Lab post Flora North America (Semple et al. 2017). In FNA, Semple & Cook (2006) included S. jejunifolia, S. pallida, and S. rigidiuscula within S. speciosa. The showy goldenrod retains its large lower stem leaves through flowering. The fruits are glabrous except for a single populations in southern Maine. The other three species, in the S. speciosa complex have very sparsely to moderately hairy fruits. The species includes two ploidy levels; diploids (2n=18) occur east of the Appalachians; tetraploids (2n=36) occur in and west of the Appalachians and in the northeastern part of the range.
Semple et al. (2017) included S. speciosa in a multivariate analysis with S. hispida and S. sciaphila. Semple and Cook (2022) published a cytogeography maps for S. speciosa and related species. In a polygenomic phylogeny of Solidago, S. speciosa came out in a strongly supported branch with S. erecta.
Semple, J.C., L. Tong, and Y.A. Chong. 2017. Multivariate studies of Solidago subsect. Squarrosae. I. The Solidago speciosa complex (Asteraceae: Astereae). Phytoneuron 2017-18: 1–23.
Semple, J.C., L. Tong, Y. A. Chong and M. Kaddoura. 2017. Multivariate studies of Solidago subsect. Squarrosae. II. The Solidago bicolor–S. hispida complex (Asteraceae: Astereae). Phytoneuron 2017-33: 1–44.
Semple, J.C. and R.E. Cook. 2022. The cytogeography of Solidago sect. Erectae, sect. Villosicarpae, sect. Squarrosae, and sect. Brintonia (Asteraceae: Astereae). Taxonomy 2: 261–278.
Semple, J.C., McMinn-Sauder, H., Stover, M., Lemmon, A., Lemmon E., and J. B. Beck. 2023. Goldenrod herbariomics: Hybrid-sequence capture reveals the phylogeny of diploid Solidago. Amer. J. Bot. 110(7): e16164.https://doi.org/10.1002/ajb2.16164
Last revised 18 May 2025 by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated
1-6. Solidago speciosa. 1. Tall shoots, Long Is., New York. 2. Basal stem leaves, Semple 11613 (NCU), Mecklenburg Co., Virginia. 3. Showy inflorescence, Semple 11568, Monroe Co., Tennessee. 4. Heads, Virginia. 5. Large bee visiting heads, pollinator, Semple 11862, Lawrence Co., Alabama. 6. Range map.