''Malacothamnus palmeri'' is a species of flowering plant in the mallow family known by the common names Cambria bushmallow and Palmer's bushmallow. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to San Luis Obispo County, California, where it is known from the Santa Lucia Mountains.Morse, K. 2021
A morphological assessment of the Malacothamnus palmeri complex (Malvaceae).
Crossosoma 44: 1–27.Morse, K. 2023
Malacothamnus Volume 3: A Revised Treatment of the Genus Malacothamnus (Malvaceae) Based on Morphological and Phylogenetic Evidence.
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Taxonomy

''Malacothamnus palmeri'' was first described in 1877 as ''Malvastrum palmeri''. In some treatments, '' Malacothamnus involucratus'' and ''

Malacothamnus lucianus ''Malacothamnus lucianus'' is a species of flowering plant in the mallow family known by the common names Santa Lucia bushmallow and Arroyo Seco bushmallow and by the cultivar name Hanging Valley bushmallow. It is endemic to Monterey County, Cal ...

'' 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 ds. The Jepson Manual: Vascular Plants of California, 884–885. University of California Press.

Identification

''Malacothamnus palmeri'' is distinguished from the rest of the genus by the combination of a capitate to subcapitate inflorescence, glandular trichomes <=0.1 mm, and the adaxial (upper) surface of mature leaves having dense stellate trichomes. ''Malacothamnus palmeri'' is distinguished from ''Malacothamnus involucratus'' by having much denser stellate trichomes on the adaxial surface of mature leaves and by generally having the widest stipular bracts <=6.5 mm wide whereas ''Malacothamnus involucratus'' generally has sparse stellate trichomes on the adaxial surface of mature leaves and the widest stipular bracts are generally >=7mm wide. ''Malacothamnus palmeri'' is distinguished from ''Malacothamnus lucianus'' by having glandular trichomes <0.1 mm and most stellate trichome rays on the stem <1 mm whereas ''Malacothamnus lucianus'' has glandular trichomes 0.3-1.4 mm and many stellate trichome rays on the stem 1–3 mm.

References

External links

Identification guide to ''Malacothamnus'' with maps and photosCalflora Profile: Malacothamnus palmeriCalphotos image gallery for ''Malacothamnus palmeri''
palmeri Endemic flora of California Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of San Luis Obispo County, California ~ Flora without expected TNC conservation status {{Malveae-stub