''Astragalus'' is a large genus of over 3,000 species of

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

s and small

shrub A shrub or 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 by their multiple ...

s, belonging to the

legume Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consum ...

family

Fabaceae Fabaceae () or Leguminosae,International Code of Nomen ...

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 The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...

. 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, an alkaloid harmful to livestock. Worldwide, swainsonine is produced by a small number of species, most of them in three genera of the ...

(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 g ...

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

vine A vine 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 themselves, for instance, when used in wicker work.Jackson; Benjamin; Da ...

-like than ''Astragalus''.

Description

Most species in the genus have

pinnately Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

compound leaves. There are annual and perennial species. The flowers are formed in clusters in a

raceme A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...

, each flower typical of the legume family, with three types of petals: banner, wings, and keel. The

calyx CALYX, Inc. is a non-profit publisher of art and literature by women founded in 1976 based in Corvallis, Oregon. CALYX publishes both '' CALYX, A Journal of Art and Literature by Women'' twice a year and CALYX Books, which publishes one to three ...

is tubular or bell-shaped.

Taxonomy

The genus was formally described in 1753 by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

in his ''

Species Plantarum ' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genus, genera. It is the first work to consistently apply binomial nomenclature ...

''. The name ''Astragalus'' is

Greek Greek may refer to: 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 of all kno ...

, 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 ...

production.

Selected species

Ecology

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

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e of some

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

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 have t ...

'': '' 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 may refer to: * ''Astragalus'' (plant), a large genus of herbs and small shrubs *Astragalus (bone), the talus or ankle bone See also *Astragal An astragal is a Moulding (decorative), moulding profile composed of a half-round surf ...

''.

Uses

Traditional medicine

Astragalus has been used in

traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medicine, alternative medical practice drawn from traditional medicine in China. A large share of its claims are pseudoscientific, with the majority of treatments having no robust evidence ...

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

Extract An extract (essence) is a substance made by extracting a part of a raw material, often by using a solvent such as ethanol, oil or water. Extracts may be sold as tinctures or absolutes or dried and powdered. The aromatic principles of ma ...

s of astragalus

root In vascular plants, the roots are the plant organ, 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 bel ...

include diverse

phytochemical Phytochemicals are naturally-occurring chemicals present in or extracted from plants. Some phytochemicals are nutrients for the plant, while others are metabolites produced to enhance plant survivability and reproduction. The fields of ext ...

s, such as

saponin Saponins (Latin ''sapon'', 'soap' + ''-in'', 'one of') are bitter-tasting, usually toxic plant-derived secondary metabolites. They are organic chemicals that become foamy when agitated in water and have high molecular weight. They are present ...

s and

isoflavone Isoflavones are a type of naturally-occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones occur in many plant species, but are especially high in soybeans. Although isoflavones and closely-related phytoestrogens ar ...

flavonoid Flavonoids (or bioflavonoids; from the Latin word ''flavus'', meaning yellow, their color in nature) are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans. Chemically, flavonoids ...

s, 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 process ...

in nursing mothers. There is no valid clinical evidence to indicate such use is effective or safe for the mother or infant.

Dietary supplement A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients eithe ...

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 esophagus, stomach, small intestine, large intestine and rectum; and the accessory organs of digestion, the liver, ...

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

, and

allergic reaction Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...

s may occur. Because astragalus may affect regulation of

blood sugar The blood sugar level, blood sugar concentration, blood glucose level, or glycemia is the measure of glucose concentrated in the blood. The body tightly regulates blood glucose levels as a part of metabolic homeostasis. For a 70 kg (1 ...

and

blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...

, it may be risky for people with

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

diabetes Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...

, or

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

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 systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic ...

, such as medications used by people being treated for

cancer Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Po ...

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 org ...

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 subst ...

, such as those found in the United States containing the

neurotoxin Neurotoxins are toxins that are destructive to nervous tissue, nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insult (medical), insultsSpencer 2000 that can adversely affect function ...

swainsonine Swainsonine is an indolizidine alkaloid. It is a potent inhibitor of Golgi alpha-mannosidase II, an immunomodulator, and a potential chemotherapy drug. As a toxin in locoweed (likely its primary toxin) it also is a significant cause of econo ...

, which causes "locoweed" poisoning in animals. Some astragalus species may contain high levels of

selenium Selenium is a chemical element; it has symbol (chemistry), symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elem ...

, 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 th ...

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 oncology, cancer treatment and research institution in Manhattan in New York City. MSKCC is one of 72 National Cancer Institute–NCI-designated Cancer Center, designated Comprehen ...

Memorial Sloan Kettering Cancer Center {{Authority control Dietary supplements Fabaceae genera Forages Medicinal plants Plants used in traditional Chinese medicine Taxa named by Carl Linnaeus