Malacothamnus palmeri was first described in 1877 as Malvastrum palmeri. In some treatments, Malacothamnus involucratus and Malacothamnus lucianus have been treated as varieties of or synonyms of Malacothamnus palmeri. In 2021 morphological analyses revealed these to be three morphologically and geographically distinct species.Kearney, T. H. 1951. “The Genus Malacothamnus, Greene (Malvaceae).” Leaflets of Western Botany VI (6):113–40.Kearney, T. H. 1955. “Notes on Malvaceae VII: A New Variety in Malacothamnus.” Leaflets of Western Botany VII (12):289–90.Bates, D. M. 2015. “Malacothamnus.” In Flora of North America North of Mexico, edited by Flora of North America Editorial Committee, 6:280–85. New York and Oxford.Slotta, T. 2012. Malacothamnus. In B. Baldwin, D. Goldman, D. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken [eds.], The Jepson Manual: Vascular Plants of California, 884–885. University of California Press.
