BRIT Press. “Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Volume 7, Potpourri: Keys, History, Authors, Artists, Collectors, Beardtongues, Glossary, Indices”. Journal of the Botanical Research Institute of Texas, vol. 12, no. 2, Nov. 2018, p. 548, doi:10.17348/jbrit.v12.i2.958.