- ↑ Watson, S., 1871United States Geological Expolration [sic] of the Fortieth Parallel (V). Botany.
- ↑ 2.0 2.1 Roskov Y., Kunze T., Orrell T., Abucay L., Paglinawan L., Culham A., Bailly N., Kirk P., Bourgoin T., Baillargeon G., Decock W., De Wever A., Didžiulis V. (ed) (2014). "Species 2000 & ITIS [[Catalogue of Life]]: 2014 Annual Checklist". Species 2000: Reading, UK. Ginkuhà 26 Mayo 2014. CS1 maint: multiple names: authors list (link) CS1 maint: extra text: authors list (link)
- ↑ ITIS: The Integrated Taxonomic Information System. Orrell T. (custodian), 26 Abril 2011