''Malacothamnus densiflorus'' is a species of flowering plant in the mallow family, which has two varieties. 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 the Peninsular Ranges of southwestern

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

and northwestern

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

. Morse, K. 2023
Malacothamnus Volume 3: A Revised Treatment of the Genus Malacothamnus (Malvaceae) Based on Morphological and Phylogenetic Evidence.
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Varieties

Two varieties are recognized in ''Malacothamnus densiflorus'': ''Malacothamnus densiflorus'' var. ''densiflorus'' and ''Malacothamnus densiflorus'' var. ''viscidus''. The geographic ranges of these varieties only overlap slightly. ''Malacothamnus densiflorus'' var. ''densiflorus'' is known by the common names few-rayed bushmallow, many-flowered bushmallow, and dense-flowered bushmallow. It can be mostly distinguished from the rest of the genus by the nonglandular

trichomes Trichomes (); ) are fine outgrowths or appendages on plants, algae, lichens, and certain protists. They are of diverse structure and function. Examples are hairs, glandular hairs, scales, and papillae. A covering of any kind of hair on a plant ...

on the abaxial calyx surface, which are relatively long, relatively sparse (especially on the calyx tube), and simple to relatively few-rayed. The common name few-rayed bushmallow comes from this distinctive character. It is distinguished from ''M. densiflorus'' var. ''viscidus'' by having sparser nonglandular trichomes on the abaxial surface of the calyx tube and shorter glandular trichomes overall. ''Malacothamnus densiflorus'' var. ''viscidus'' is known by the common name emerald unicorn bushmallow, which is named after the glandular trichomes that, after drying, sometimes resemble unicorn horns made of emerald. It can be distinguished from most of the rest of the genus by the combination of a spike-like inflorescence and relatively long glandular trichomes. ''Malacothamnus densiflorus'' var. ''viscidus'' is endemic to San Diego County, California and adjacent Baja California on

Otay Mountain Otay Mountain is a mountain located in San Diego County, California. It is the highest summit of the San Ysidro Mountains. The mountain is located in the Otay Mountain Wilderness Area. The physical border separating Mexico and the United Stat ...

northward to near the town of

Jamul, California Jamul (; Kumeyaay: ''Ha-mul'', meaning "sweet water") is a census-designated place (CDP) in San Diego County, California, United States. Jamul had a population of 6,163 at the 2010 census. Jamul suffered from the Valley Fire, one of the 2020 Calif ...

References

External links

Identification guide to ''Malacothamnus'' with maps and photosCalphotos image gallery for ''Malacothamnus densiflorus'' var. ''densiflorus''Calphotos image gallery for ''Malacothamnus densiflorus'' var. ''viscidus''
densiflorus Flora of California Flora of Baja California Natural history of the California chaparral and woodlands Natural history of the Peninsular Ranges Flora and fauna of the San Jacinto Mountains Flora without expected TNC conservation status {{Malveae-stub