''Astragalus ripleyi'' is a species of flowering plant in the

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 ...

family known by the common name Ripley's milkvetch. It is native to southern Colorado and northern New Mexico in the United States.

Description

This plant is a perennial herb growing up to one meter tall with stems arising from an underground

caudex A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is m ...

. This caudex branches into stems underground and has been called a

rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

. The leaves are compound, each made up of up to 19 leaflets. The plant is mostly hairy, with silvery hairs giving it a grayish appearance. The flowers are yellow and between 1 and 2 centimeters long. The fruit is a flat pod up to 3 centimeters long. Each fruit has a long stipe, the area between the stem and the fruit. Flowering occurs in June and July.

Habitat

This plant occurs in the southern Rocky Mountains. It grows in ponderosa pine savanna, pinyon-juniper woodlands, shrublands, sagebrush, and meadows. It is often found next to

shrub A shrub (often also called a bush) is a small-to-medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees ...

s such as '' Artemisia tridentata'', '' Quercus gambelii'', '' Chrysothamnus'' spp., and '' Juniperus'' spp. These shrubs may form a microclimate that the milkvetch can survive in, or it may remain beneath shrubs because those out in the open are

grazed In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other f ...

by animals. It grows in areas with high plant biodiversity. Trees in the area may include '' Abies concolor'', '' Pinus edulis'', '' Populus tremuloides'', and '' Pseudotsuga menziesii''. Shrubs include '' Artemisia'' spp., ''

Chrysothamnus greenei ''Chrysothamnus greenei'', called Greene's rabbitbrush , is a North American species of flowering plants in the tribe Astereae within the family Asteraceae. It has been found in eastern California (Mono + Inyo Counties), Nevada, Arizona, New Mex ...

'', '' Chrysothamnus nauseosus'', '' Cercocarpus montanus'', ''

Potentilla fruticosa ''Dasiphora fruticosa'' is a species of hardy deciduous flowering shrub in the family Rosaceae, native to the cool temperate and subarctic regions of the northern hemisphere, often growing at high altitudes in mountains. ''Dasiphora fruticosa'' ...

'', and '' Rhus trilobata''. Forbs include '' Machaeranthera bigelovii'', ''

Astragalus drummondii ''Astragalus drummondii'' is a species of flowering plant in the legume family known by the common name Drummond's milkvetch. The botanist Thomas Drummond first identified the plant during his travels in North America from 1825 to 1835, the year ...

'', '' Astragalus hallii'', ''

Astragalus lonchocarpus ''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 ...

'', '' Gutierrezia sarothrae'', '' Heterotheca villosa'', ''

Hymenoxys odorata ''Hymenoxys odorata'' is a species of flowering plant in the daisy family known by the common names bitter rubberweed and western bitterweed. It is native to the southwestern and south-central United States from southern California to Texas north ...

'', '' Picradenia richardsonii'', ''

Eriogonum racemosum ''Eriogonum'' is a genus of flowering plants in the family Polygonaceae. The genus is found in North America and is known as wild buckwheat. This is a highly species-rich genus, and indications are that active speciation is continuing. It in ...

'', '' Linum lewisii'', and ''

Melilotus officinalis ''Melilotus officinalis'', known as sweet yellow clover, yellow melilot, ribbed melilot and common melilot, is a species of legume native to Eurasia and introduced in North America, Africa, and Australia. Description ''Melilotus officinalis'' c ...

''. The plant only occurs on volcanic soils.Ladyman, J. A. R. (2003, December 16)
''Astragalus ripleyi'' Barneby (Ripley’s milkvetch): A technical conservation assessment.
nline USDA Forest Service, Rocky Mountain Region.

Distribution

This species is only found in Taos and Rio Arriba Counties in New Mexico and Conejos County, Colorado. It can be locally abundant. There are an estimated 10,000 individuals.

Conservation

This plant is attractive to many types of animals and it may be heavily grazed. Grazing, especially by sheep, is a threat to its survival. Wildlife also consumes it. Another threat is invasive plant species, especially species of clover. Other threats include fire suppression and any force that causes erosion in the habitat.

References

External links

USDA Plants Profile
{{Taxonbar, from=Q4811290 ripleyi Flora of Colorado Flora of New Mexico