''Astragalus ertterae'' is a rare 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 tempe ...

known by the common name Walker Pass milkvetch. 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 elsew ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

, where it is known from only three occurrences near

Walker Pass Walker Pass (el. ) is a mountain pass by Lake Isabella in the southern Sierra Nevada. It is located in northeastern Kern County, approximately 53 mi (85 km) ENE of Bakersfield and 10 mi (16 km) WNW of Ridgecrest. The pass prov ...

in the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

. It is endangered by trampling, trail use, and also grazing. It is only found in the northeast corner of

Kern county Kern County is a county located in the U.S. state of California. As of the 2020 census, the population was 909,235. Its county seat is Bakersfield. Kern County comprises the Bakersfield, California, Metropolitan statistical area. The county sp ...

, in the

. It's bloom period is April and May.

Description

''Astragalus ertterae'' is hairy perennial herb with a stem no more than 10 centimeters long, much of which grows underground. There are 4 or 5 leaves which are a few centimeters long and made up of several oval-shaped leaflets. The dense

inflorescence An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...

holds up to 17 cream-colored flowers, each about a centimeter long. The fruit is a swollen, hairless

legume A legume () is a plant in the family Fabaceae (or Leguminosae), or the fruit or seed of such a plant. When used as a dry grain, the seed is also called a pulse. Legumes are grown agriculturally, primarily for human consumption, for livestock f ...

pod which dries to a leathery texture. It is closely morphologically related to Astragalus bicristatus.

References

External links

CalFlora Database: ''Astragalus ertterae'' (Walker Pass milk vetch)Jepson Manual eFlora (TJM2) treatment - ''Astragalus ertterae''The Nature ConservancyUSDA Plants Profile for ''Astragalus ertterae'' (Walker Pass milk vetch)
*{http://calphotos.berkeley.edu/cgi-bin/img_query?where-taxon=Astragalus+ertterae&where-anno=1 UC Photos gallery — ''Astragalus ertterae''] Astragalus, ertterae Endemic flora of California Flora of the Sierra Nevada (United States) Natural history of Kern County, California Critically endangered flora of California {{Astragalus-stub