Great Basin Eurybioid Asters

Herrickia Wooten & Standley is small North American genus native to the Great Basin intermountain region of the western United States (Brouillet 2006, FNA). All members have 2n = 18 (x=9).

Generic status for Herrickia was generally not accepted and has only recently been expanded and reinstated. Brouillet, Urbatsch & Roberts (2004) presented the results of a nrDNA sequence analysis that sorted out the relationships among species at the base of the Machaerantherinae-Symphyotrichinae Clade. Oreostemma, Herrickia, Eurybia and Triniteurybia formed a grade of genera leading to the Machaerantherinae genera with lower base numbers of x = 6, 5 and 4 (e.g., Machaeranthera sensu Morgan and Hartman (2003 Sida 20:1287-1416.), Xanthisma sensu Morgan and Hartman (2003), Isocoma, Haplopappus, Lessingia, etc.).

As originally proposed by Wooten and Standley (1913) Herrickia included just H. horrida, which has sharply toothed-spinulose leaves similar to those of many Machaerantherinae taxa. Nesom (1994) included the genus as a section within Eurybia and added Eucephalus glauca and Eucephalus wasatchensis to it.  Brouillet et al. (2001) and Semple et al. (2002) indicated that the phylogeny of Eurybia sensu Nesom was unresolved. Brouillet et al.(2004) and Seliah and Brouillet (2008) clarified the phylogeny of the Great Basin eurybioid asters.

The treatment here follows Brouillet (2006 Flora North America).

Brouillet, L., L. Urbatsch and R.P. Roberts. 2004. Tonestus kingii and T. aberrans are related to Eurybia and the Machaerantherinae (Asteraceae: Astereae) based on NRDNA (ITS and ETS) data: reinstatement of Herrickia and a new genus, Triniteurybia. Sida 21: 889-900.

Brouillet, L.  2006. Herrickia Wooton & Standley. pp. 361--365. In Flora North America Editorial Committee, eds. Flora of North America. Vol. 20. Asteraceae, Part 2. Astereae and Senecioneae. Oxford University Press, New York.

Selliah, S. & Brouillet, L. 2008. Molecular phylogeny of the North American eurybioid asters, Oreostemma, Herrickia, Eurybia, and Triniteurybia (Asteraceae, Astereae) based on the ITS and 3’ETS nuclear ribosomal regions. Canadian Journal of Botany 86: 901-915.

revised 28 January by J.C. Semple

© 2014 J.C. Semple, including all photographs unless otherwise indicated