''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 only 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 foun ...

to the

Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Pacific Coast Range ...

of southwestern

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and northwestern

Baja California Baja California, officially the Free and Sovereign State of Baja California, is a state in Mexico. It is the northwesternmost of the 32 federal entities of Mexico. Before becoming a state in 1952, the area was known as the North Territory of B ...

. 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 San Diego County (), officially the County of San Diego, is a county (United States), county in the southwest corner of the U.S. state of California, north to its Mexico-United States border, border with Mexico. As of the 2020 United States Cen ...

and adjacent Baja California on

Otay Mountain Otay Mountain is a mountain 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 Mexico-United States border runs along the south face of th ...

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 6,179 at the 2020 census, up from 6,163 at the 2010 census. Jamul suffered from t ...

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 {{Malveae-stub