Astragalus montii is a rare species of flowering plant in the legume family

Fabaceae

The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...

 known by the common name heliotrope milkvetch. It is endemic 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...

 in the United States, where there are only three known populations. It is a federally listed threatened species of the United States. This species is often treated as a variety of Astragalus limnocharis.

This plant is a small perennial herb growing just a few centimeters tall. The leaves are pinnately compound, with several pairs of leaflets. 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...

 contains two to eight flowers which are pinkish purple in color with white wing-tips. The fruit is an inflated legume pod which is pinkish in color with purple mottling. Blooming occurs in the summer months. The flowers are pollinated

Pollination

Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...

 by a number of native bee

Bee

Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

 species, especially genus Osmia.

This plant is endemic to the Wasatch Plateau of central Utah. The three populations are located in an eight-mile strech of mountainous habitat in the Manti-La Sal National Forest

Manti-La Sal National Forest

The Manti-La Sal National Forest covers 1,270,646 acres and is located in the central and southeastern parts of the U.S. state of Utah and the extreme western part of Colorado...

. There is a population on White Mountain, one on Heliotrope Mountain, and one on the ridgecrest connecting Heliotrope Mountain to Ferron Mountain. The subalpine

Subalpine

The subalpine zone is the biotic zone immediately below tree line around the world. Species that occur in this zone depend on the location of the zone on the Earth, for example, Snow Gum in Australia, or Subalpine Larch, Mountain Hemlock and Subalpine Fir in western North America.Trees in the...

 habitat is made up of limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 shale barrens near the timberline. Other plants in the habitat include cushion phlox

Phlox pulvinata

Phlox pulvinata is a species of phlox known by the common name cushion phlox. It is native to the western United States where it grows in mountain and plateau habitat, in rocky subalpine and alpine climates, including exposed tundra habitat. It is a perennial herb taking a flat, dense, cushionlike...

 (Phlox pulvinata), alpine false springparsley (Pseudocymopterus montanus), woolly groundsel

Packera cana

Packera cana is a species of flowering plant in the aster family known by the common name woolly groundsel. It is native to western and central North America, where it can be found in a wide array of habitat types at all elevations from grassland to the alpine climates of mountain peaks.It is a...

 (Packera cana), spiny milkvetch

Astragalus kentrophyta

Astragalus kentrophyta is a species of milkvetch known by the common name spiny milkvetch. It is native to western North America from central to west Canada, to California, to New Mexico. It grows in rocky mountainous areas, such as the Sierra Nevada, and on plateaus.-Description:This perennial...

 (Astragalus kentrophyta), shortstem buckwheat (Eriogonum brevicaule), Bear River fleabane (Erigeron ursinus), sheep cinquefoil (Potentilla ovina), and elegant cinquefoil (Potentilla concinna).

The main threat to the species is energy development. The area is experiencing active oil and gas exploration. This is the main reason the species was added to the Endangered Species List with threatened status in 1987.