''Astragalus danicus'', known as purple milk-vetch, is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

in the family

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

(legumes), which is native to

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

Description

''Astragalus danicus'' is a perennial herb. It grows to about tall with pinnate 3–7 cm compound leaves having 13–27 5-12mm long hairy leaflets. Its

flowers Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

are usually in shades of blue and purple, rarely white, long and clustered in short, compact racemes, looking like a single composite flower. They are followed by dark brown, fruit pods long, with white hairs. There is some evidence that seeds persist in the soil seed bank, but seed dispersal is poor (generally only 50 cm).BSBI Species Accounts Archive
/ref>Plant Life International - Species Fact Sheet
/ref>

Habitat and distribution

''Astragalus danicus'' ranges across Europe from

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

and subarctic

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

south to the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

and central

Ukraine Ukraine is a country in Eastern Europe. It is the List of European countries by area, second-largest country in Europe after Russia, which Russia–Ukraine border, borders it to the east and northeast. Ukraine also borders Belarus to the nor ...

. It grows on short, unimproved and dry

grassland A grassland is an area where the vegetation is dominance (ecology), dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes such as clover, and other Herbaceo ...

, usually over

limestone Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...

, but can also be found on

sand dunes A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, flat ...

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

sea cliffs,

machair A machair (; sometimes machar in English) is a fertile low-lying grassy plain found on part of the northwestern coastlines of Ireland and Scotland, particularly the Outer Hebrides. The best examples are found on North and South Uist, Harris ...

and over mica-schist. Rarely it has been found on woodland rides and firing ranges. It grows to an altitude of just 710m. It is unable to compete with taller plants and this seems to be the main reason it is not found in habitats with acidic or fertilised soils.Online Atlas of the British and Irish Flora
/ref>

Ecology

''Astragalus danicus'' flowers provide nectar and are visited by many

insects Insects (from Latin ') are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed ...

. This species is considered to be mainly pollinated by

bees Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...

. In the UK the grasslands where ''A. danicus'' is found are predominantly ''

Festuca ''Festuca'' (fescue) is a genus of flowering plants belonging to the grass family Poaceae (subfamily Pooideae). They are evergreen or herbaceous perennial tufted grasses with a height range of and a cosmopolitan distribution, occurring on ...

'', '' Bromopsis'' and ''

Brachypodium ''Brachypodium'' is a genus of plants in the grass family, widespread across much of Africa, Eurasia, and Latin America. The genus is classified in its own tribe Brachypodieae. Flimsy upright stems form tussocks. Flowers appear in compact spi ...

'' grasslands. The species is non-toxic and its common name in English comes from the popular belief in history that

cows Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are called co ...

fed with purple milk-vetch yielded more

milk Milk is a white liquid food produced by the mammary glands of lactating mammals. It is the primary source of nutrition for young mammals (including breastfeeding, breastfed human infants) before they are able to digestion, digest solid food. ...

Conservation

In the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

''Astragalus danicus'' has vulnerable status and has been a Biodiversity Action Plan priority species since 2007. There ''Astragalus danicus'' has declined since the start of the

enclosure Enclosure or inclosure is a term, used in English landownership, that refers to the appropriation of "waste" or "common land", enclosing it, and by doing so depriving commoners of their traditional rights of access and usage. Agreements to enc ...

farming system in the 18th century, however declines accelerated in some parts of its range since the 1930s, due to agricultural improvement and in some cases due to land going without grazing (the species can only grow in short vegetation).

Herbal medicine

''Astragalus danicus'' has been indicated to have a number of beneficial medicinal effects, particularly in combatting

high blood pressure Hypertension, also known as high blood pressure, is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms itself. It is, however, a major ri ...

, however health supplements labelled as 'milk-vetch' may contain extracts from a different species in the genus ''

Astragalus Astragalus may refer to: * ''Astragalus'' (plant), a large genus of herbs and small shrubs *Astragalus (bone) The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known ...

''. Some other species in the genus ''Astragalus'' are known to be toxic to animals and referred to in the US as 'locoweed'.

Etymology

There are a few explanations for the meaning of the genus name ''Astragalus''. Some say it comes from the

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

'astragalos' meaning neck

vertebra Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

or ankle joint, either because the shape of the flower clusters is similar to a vertebra or because the shape of the seeds is similar to an ankle bone. Others say that 'astragalus' is an amalgamation of the Ancient Greek words 'aster' and 'gala' meaning 'star' and 'milk' respectively. The species epithet ''danicus'' is Latin for ' Danish', presumably it was first identified in Denmark.Latin Dictionary - danicus
/ref> The English common name comes from the popular belief in history that

fed with purple milk-vetch yielded more

References

{{Taxonbar, from=Q163342 danicus