''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 The Faboideae are a subfamily of the flowering plant family Fabaceae or Leguminosae. An acceptable alternative name for the subfamily is Papilionoideae, or Papilionaceae when this group of plants is treated as a family. This subfamily is widely ...

. It is the largest genus of plants in terms of described species. The genus is native to temperate regions of the Northern Hemisphere. Common names include milkvetch (most species),

locoweed Locoweed (also crazyweed and loco) is a common name in North America for any plant that produces swainsonine, a phytotoxin harmful to livestock. Worldwide, swainsonine is produced by a small number of species, most of them in three genera of the f ...

(in North America, some species) and goat's-thorn ( ''A. gummifer'', ''A. tragacantha''). Some pale-flowered vetches (''

Vicia ''Vicia'' is a genus of over 240 species of flowering plants that are part of the legume family (Fabaceae), and which are commonly known as vetches. Member species are native to Europe, North America, South America, Asia and Africa. Some other ...

'' spp.) are similar in appearance, but they are more

vine A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themsel ...

-like than ''Astragalus''.

Description

Most species in the genus have pinnately compound leaves. There are annual and perennial species. The flowers are formed in clusters in a raceme, each flower typical of the legume family, with three types of petals: banner, wings, and keel. The calyx is tubular or bell-shaped.

Ecology

''Astragalus'' species are used as food plants by the

larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. ...

e of some Lepidoptera species including many case-bearing moths of the genus ''

Coleophora ''Coleophora'' is a very large genus of moths of the family Coleophoridae. It contains some 1,350 described species. The genus is represented on all continents, but the majority are found in the Nearctic and Palaearctic regions. Many authors ...

'': '' C. cartilaginella'', '' C. colutella'', '' C. euryaula'', and '' C. onobrychiella'' feed exclusively on ''Astragalus'', '' C. astragalella'' and '' C. gallipennella'' feed exclusively on the species ''

Astragalus glycyphyllos ''Astragalus glycyphyllos'' (liquorice milkvetch, wild liquorice, wild licorice) is a flowering plant in the family Fabaceae, native to Europe. It is a perennial herbaceous Herbaceous plants are vascular plants that have no persistent woody ...

'', and '' C. hippodromica'' is limited to ''

Astragalus gombo ''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 ...

''.

Taxonomy

The genus was formally described in 1753 by

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his Nobility#Ennoblement, ennoblement in 1761 as Carl von Linné#Blunt, Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalise ...

in his '' Species Plantarum''. The name ''Astragalus'' is

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

, an old name for this group of plants which were believed to have a positive effect on

goat milk Goat milk is the milk of domestic goats. Goats produce about 2% of the world's total annual milk supply. Some goats are bred specifically for milk. Goat milk naturally has small, well-emulsified fat globules, which means the cream will stay i ...

production.

Selected species

Uses

Traditional medicine

Astragalus has been used in

traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medical practice drawn from traditional medicine in China. It has been described as "fraught with pseudoscience", with the majority of its treatments having no logical mechanism of acti ...

over centuries to treat various disorders, but there is no high-quality evidence that it is effective or safe for any medical purpose.

Phytochemicals and supplements

Extracts of astragalus

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...

include diverse phytochemicals, such as saponins and

isoflavone Isoflavones are substituted derivatives of isoflavone, a type of naturally occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones are produced almost exclusively by the members of the bean family, Fabaceae (Leguminosae) ...

flavonoids, which are purported in traditional practices to increase

lactation Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The proces ...

in nursing mothers. There is no valid clinical evidence to indicate such use is effective or safe for the mother or infant. Dietary supplement products containing astragalus extracts may not have been adequately tested for efficacy, safety, purity or consistency. The root extracts of astragalus may be used in soups, teas or sold in capsules.

Side effects and toxicology

Although astragalus supplements are generally well tolerated, mild

gastrointestinal upset Gastrointestinal diseases (abbrev. GI diseases or GI illnesses) refer to diseases involving the gastrointestinal tract, namely the oesophagus, stomach, small intestine, large intestine and rectum, and the accessory organs of digestion, the liver, ...

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin w ...

, and

allergic reaction Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

s may occur. Because astragalus may affect regulation of

blood sugar Glycaemia, also known as blood sugar level, blood sugar concentration, or blood glucose level is the measure of glucose concentrated in the blood of humans or other animals. Approximately 4 grams of glucose, a simple sugar, is present in the blo ...

and blood pressure, it may be risky for people with

blood disorder Hematologic diseases are disorders which primarily affect the blood & blood-forming organs. Hematologic diseases include rare genetic disorders, anemia, HIV, sickle cell disease & complications from chemotherapy or transfusions. Myeloid * Hemog ...

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

, or hypertension to use it as a supplement. Astragalus may interact with prescribed drugs that suppress the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splint ...

, such as medications used by people being treated for

cancer Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

or recovery from

organ transplant Organ transplantation is a medical procedure in which an organ (anatomy), organ is removed from one body and placed in the body of a recipient, to replace a damaged or missing organ. The donor and recipient may be at the same location, or organ ...

s. Some astragalus species can be

toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...

, such as those found in the United States containing the neurotoxin swainsonine, which causes "locoweed" poisoning in animals. Some astragalus species may contain high levels of

selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...

, possibly causing toxicity.

Ornamental use

Several species, including ''A. alpinus'' (bluish-purple flowers), ''A. hypoglottis'' (purple flowers), and ''A. lotoides'', are grown as

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

s in gardens.

Notes

References

External links

''Astragalus''
— Genus of vascular plants
''Astragalus'' – Clinical summary and constituents

MSKCC Memorial Sloan Kettering Cancer Center (MSK or MSKCC) is a cancer treatment and research institution in the borough of Manhattan in New York City, founded in 1884 as the New York Cancer Hospital. MSKCC is one of 52 National Cancer Institute– ...

Memorial Sloan Kettering Cancer Center {{Taxonbar, from=Q157184 Dietary supplements Fabaceae genera Forages Medicinal plants Plants used in traditional Chinese medicine Taxa named by Carl Linnaeus