''Astragalus albens'' is a species of

milkvetch ''Astragalus'' is a large genus of over 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae and the subfamily Faboideae. It is the largest genus of plants in terms of described species. The genus is native to temper ...

known by the common names Cushenbury milkvetch and silvery-white milkvetch.

Distribution

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 ...

San Bernardino County, California San Bernardino County ( ), officially the County of San Bernardino and sometimes abbreviated as S.B. County, is a County (United States), county located in the Southern California, southern portion of the U.S. state of California, and is locat ...

, where it is known from the northern slopes of the

San Bernardino Mountains The San Bernardino Mountains are a high and rugged mountain range in Southern California in the United States. Situated north and northeast of San Bernardino and spanning two California counties, the range tops out at at San Gorgonio Mountain ...

near the settlement of Cushenbury. Most of the plants are located in the woodland and scrub of the slopes between

Big Bear Big Bear, also known as (; – 17 January 1888), was a powerful and popular Cree chief who played many pivotal roles in Canadian history. He was appointed to chief of his band at the age of 40 upon the death of his father, Black Powder, u ...

in the mountains and

Lucerne Valley Lucerne Valley is a census-designated place (CDP) and valley landform in the southern Mojave Desert, in western San Bernardino County, California. Geography The geographic valley is defined by the surrounding Granite Mountains, Ord Mountains ...

in the

Mojave Desert The Mojave Desert (; ; ) is a desert in the rain shadow of the southern Sierra Nevada mountains and Transverse Ranges in the Southwestern United States. Named for the Indigenous peoples of the Americas, indigenous Mohave people, it is located pr ...

at the foot of the range. It grows in habitat rich in

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

rock. It is a federally listed

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

which is known from 30 to 50 populations.Center for Plant Conservation Profile
There are a total of about 7000 plants, fewer in

drought A drought is a period of drier-than-normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, ...

years.The Nature Conservancy
/ref>

Description

''Astragalus albens'' is an annual or perennial herb producing a prostrate mat of delicate stems coated densely in silvery hairs. The leaves are generally a few centimeters long and made up of several gray-green oval-shaped leaflets less than a centimeter long each. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

arises upright from the low patch of foliage and bears up to 14 pealike flowers. Each flower is dark-veined light to deep purple with a spot of white or light pink in the throat. The fruit is a

legume Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consum ...

pod between one and two centimeters long. It is roughly hairy and crescent-shaped, drying to a thick papery texture.

Conservation

The main threat to this species is

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

mining, a large industry in this part of the San Bernardino Mountains. This form of mining alters the local habitat by physically removing plant life for

quarries A quarry is a type of open-pit mine in which dimension stone, rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safet ...

road construction A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. The ...

, and load dumping. It also produces major changes in the

hydrology Hydrology () is the scientific study of the movement, distribution, and management of water on Earth and other planets, including the water cycle, water resources, and drainage basin sustainability. A practitioner of hydrology is called a hydro ...

of the area and releases large amounts of carbonate dust into the air which combines with water and forms a very thin layer of what is essentially

cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...

over the habitat. Most of the populations of this plant are located on sites of active mining or sites which are targeted for mining in the future. Most of these sites are part of

San Bernardino National Forest The San Bernardino National Forest is a United States national forest in Southern California encompassing of which are federal. The forest is made up of two main divisions, the eastern portion of the San Gabriel Mountains and the San Bernar ...

, and there are plans to set aside pieces of habitat for this and other endemics. Other threats to the species include

off-road vehicle An off-road vehicle (ORV), also known as an off-highway vehicle (OHV), overland vehicle or adventure vehicle, is a type of transportation specifically engineered to navigate unpaved roads and surfaces. These include trails, forest roads, and ...

use and

urban development Urban means "related to a city". In that sense, the term may refer to: * Urban area, geographical area distinct from rural areas * Urban culture, the culture of towns and cities Urban may also refer to: General * Urban (name), a list of peop ...

References

External links

Jepson Manual Treatment — ''Astragalus albens''''Astragalus albens'' — U.C. Photo gallery
{{Taxonbar, from=Q2714866 albens Endemic flora of California Flora of the California desert regions San Bernardino Mountains Natural history of the California chaparral and woodlands Natural history of the Mojave Desert Natural history of San Bernardino County, California Natural history of the Transverse Ranges NatureServe critically imperiled species Critically endangered flora of California Plants described in 1885