Astragalus purshii
Encyclopedia
Astragalus purshii is a species of milkvetch
Astragalus
Astragalus is a large genus of about 3,000 species of herbs and small shrubs, belonging to the legume family Fabaceae, subfamily Faboideae. The genus is native to temperate regions of the Northern Hemisphere...

 known by the common names woollypod milkvetch and Pursh's milkvetch. It is native to much of western North America, including the southwestern provinces of Canada and the northwestern United States, where it is known from many types of habitat. It is common along the Columbia River in arid, shrub-steppe habitat growing in shallow soils which generally excludes sagebrush. It is a seral species preferring disturbed rocky soils.

Description

Astragalus purshii is a small perennial herb forming low matts on the ground no taller than 14 centimeters and generally less than 5 centimeters. The leaves are up to 15 centimeters long and are made up of many oval or rounded leaflets. Stems and leaflets are coated in woolly white hairs giving a silver color to the foliage.

The inflorescence
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. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...

 is a cluster of 1 to 11 pink, rose, purple, or white flowers (depending on geographic location) each between 1 and 3 centimeters long. The fruit is a legume pod up to 3 centimeters long which is coated densely in thick white hairs resembling a small rabbits-foot.

Varieties

There are many varieties of this Astragalus purshii, including:
  • A. p. var. concinnus - native to Idaho
    Idaho
    Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

     and Montana
    Montana
    Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

  • A. p. var. glareosus (syn.
    Synonym (taxonomy)
    In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...

     Astragalus glareosus) - found from British Columbia
    British Columbia
    British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

     to Utah
    Utah
    Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...

  • A. p. var. lagopinus - native to the Modoc Plateau
    Modoc Plateau
    The Modoc Plateau lies in the northeast corner of California as well as parts of Oregon and Nevada. It is a mile-high expanse of lava flows with cinder cones, juniper flats, pine forests, and seasonal lakes. The plateau is thought to have been formed approximately 25 million years ago...

    , California
  • A. p. var. lectulus - native to California
    California
    California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...

     and Nevada
    Nevada
    Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...

  • A. p. var. ophiogenes (Snake River milkvetch) - native to Oregon
    Oregon
    Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

     and Idaho
    Idaho
    Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

  • A. p. var. pumilio - endemic to Nevada
  • A. p. var. purshii - distributed throughout species range
  • A. p. var. tinctus - found throughout the western U.S.

Cultivation

It is an excellent rock garden
Rock Garden
The Rock Garden or Rock Garden of Chandigarh is a Sculpture garden in Chandigarh, India, also known as Nek Chand's Rock Garden after its founder Nek Chand, a government official who started the garden secretly in his spare time in 1957. Today it is spread over an area of forty-acres , it is...

 plant., as a serial ephemeral species, and an addition to municipal and agency sustainable landscape
Sustainable landscaping
Sustainable landscaping encompasses a variety of practices that have developed in response to environmental issues. These practices are used in every phase of landscaping, including design, construction, implementation and management of residential and commercial landscapes. Issues of...

 and restoration projects. It is also a component for reclamation projects.

Seeds do not require stratification and are tolerant of low precipitation and drought (municipal landscaping candidate to reduce water usage). Plants are hardy to -33F.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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