''Polygala'' is a large
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
flowering plant
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
s belonging to the family
Polygalaceae
The Polygalaceae or the milkwort family are made up of flowering plants in the order Fabales. They have a near-cosmopolitan range, with about 27 genera and ''ca''. 900 known species of herbs, shrubs and trees. Over half of the species are in one ...
. They are commonly known as milkworts or snakeroots. The genus is distributed widely throughout much of the world
[''Polygala''.]
Flora of China. in
temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...
zones and the
tropics
The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in
the Southern Hemisphere at S. The tropics are also referred to ...
.
[''Polygala''.]
The Jepson eFlora 2013. The genus name ''Polygala'' comes from the
ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
"much milk", as the plant was thought to increase milk yields in cattle.
Description
As traditionally
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
, ''Polygala'' includes
annual
Annual may refer to:
* Annual publication, periodical publications appearing regularly once per year
**Yearbook
** Literary annual
* Annual plant
* Annual report
* Annual giving
* Annual, Morocco, a settlement in northeastern Morocco
* Annuals (b ...
and
perennial plant
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...
s,
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,
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 themselv ...
s, and
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s.
[ The roots often have a scent reminiscent of ]wintergreen
Wintergreen is a group of aromatic plants. The term "wintergreen" once commonly referred to plants that remain green (continue photosynthesis) throughout the winter. The term "evergreen" is now more commonly used for this characteristic.
Mos ...
.[ The leaf blades are generally undivided and smooth-edged, and are alternately arranged in most species. The ]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. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed o ...
is a raceme
A raceme ( or ) or racemoid is an unbranched, 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 produced as the s ...
or spikelike array of several flowers; the occasional species bears solitary flowers.[ The flower is bilateral in shape, with two large petal-like ]sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
s on the sides, often called the "wings",[ and three smaller sepals behind. There are three ]petal
Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...
s in shades of reddish purple, yellow or white, which are joined at the bases. The lower of the three is the keel petal, which is "boat-shaped, cucullate ood-like or helmet-shaped".[ The keel petal may have a beak or a fringe on the tip.][ ]Stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filame ...
s and style
Style is a manner of doing or presenting things and may refer to:
* Architectural style, the features that make a building or structure historically identifiable
* Design, the process of creating something
* Fashion, a prevailing mode of clothing ...
are within the curve of the keel petal. The fruit is a capsule, sometimes winged. It contains two seeds,[ which are usually black, hairy and tipped with a large white ]aril
An aril (pronounced ), also called an arillus, is a specialized outgrowth from a seed that partly or completely covers the seed. An arillode or false aril is sometimes distinguished: whereas an aril grows from the attachment point of the see ...
.[ No members of this genus are known to form nitrogen-fixing nodules.]
Taxonomy
The genus ''Polygala'' was first described by Carl Linnaeus
Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
in 1754. Phylogenetic studies showed that, as traditionally circumscribed, the genus was not monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
. It had become a "wastebasket taxon
Wastebasket taxon (also called a wastebin taxon, dustbin taxon or catch-all taxon) is a term used by some taxonomists to refer to a taxon that has the sole purpose of classifying organisms that do not fit anywhere else. They are typically defined ...
"; almost all species with a flower apparently similar to those of the Papilionoideae
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 ...
– two petaloid lateral sepal
A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...
s forming 'wings', two petals forming a 'standard', and one petal forming a 'keel', plus a bilocular fruit capsule – were placed in ''Polygala'', while species with more obviously specialized features, particularly those of the fruit, were placed in other genera. In 2011, John Richard Abbott separated some more sharply defined genera from ''Polygala''.
Species
Partly because of differing circumscriptions, the reported number of valid species in the genus varies from about 350[Coelho, V. P. D. M., et al. (2008)]
Flora of Paraíba, Brazil: ''Polygala'' L.(Polygalaceae).
''Acta Botânica Brasilica'' 22(1), 225-39. (Portuguese) to 500[ to 725][Lüdtke, R., et al. (2013)]
The genus ''Polygala'' L.(Polygalaceae) in Southern Brazil.
''Hoehnea'' 40(1), 1-50. (Portuguese) or 730.[Pastore, J. F. B. and T. B. Cavalcanti. (2008)]
A New Species of ''Polygala'' (Polygalaceae) from Brazil.
''Novon'' 18(1), 90-93. The Americas have the most species, especially South America,[ with Africa second in diversity and Asia third.][
, '']Plants of the World Online
Plants of the World Online (POWO) is an online database published by the Royal Botanic Gardens, Kew. It was launched in March 2017 with the ultimate aim being "to enable users to access information on all the world's known seed-bearing plants by ...
'' accepted about 660 species in the genus ''Polygala''. These include:
Species now placed in other genera:
*''Polygala acanthoclada'' = ''Rhinotropis acanthoclada
''Rhinotropis acanthoclada'', Synonym (taxonomy), synonym ''Polygala acanthoclada'', is a species of flowering plant in the Polygalaceae, milkwort family known by the common names desert polygala and thorn milkwort.Rhinotropis californica
''Rhinotropis californica'', Synonym (taxonomy), synonym ''Polygala californica'', is a species of flowering plant in the Polygalaceae, milkwort family known by the common name California milkwort. It is native to southwestern Oregon and northern ...
''
*''Polygala chamaebuxus'' = ''Polygaloides chamaebuxus
''Polygaloides chamaebuxus'', synonym ''Polygala chamaebuxus'', the shrubby milkwort, is an ornamental plant in the family Polygalaceae. Its flowers are solitary or in pairs in the leaf axils. The inner two sepals, the wings, are upright and whi ...
''
*''Polygala paucifolia'' = ''Polygaloides paucifolia
''Polygaloides paucifolia'', Synonym (taxonomy), synonym ''Polygala paucifolia'', known as gaywings or fringed polygala, is a perennial plant of the family Polygalaceae.
Mature plants are 3 to 6 inches tall. Stems are smooth, slender and green. ...
''
*''Polygala cornuta'' = ''Rhinotropis cornuta
''Rhinotropis cornuta'', synonym ''Polygala cornuta'', is a species of flowering plant in the milkwort family known by the common name Sierra milkwort. It is native to many of the mountain ranges of California and northern Baja California, where ...
''
*''Polygala heterorhyncha'' = '' Rhinotropis heterorhyncha''
*''Polygala intermontana'' = ''Rhinotropis intermontana
''Rhinotropis intermontana'', Synonym (taxonomy), synonym ''Polygala intermontana'', is a species of flowering plant in the Polygalaceae, milkwort family known by the common name intermountain milkwort. It is native to the southwestern United Sta ...
''
*''Polygala macradenia'' = ''Hebecarpa macradenia
''Hebecarpa macradenia'', synonym ''Polygala macradenia'', the glandleaf milkwort, is a sub shrub in the milkwort family (Polygalaceae) found in the Arizona Uplands of the Sonoran Desert
The Sonoran Desert ( es, Desierto de Sonora) is a deser ...
''
*''Polygala pterolopha'' = ''Monrosia pterolopha
''Monrosia'' is a genus of flowering plants belonging to the family Polygalaceae, with the sole species ''Monrosia pterolopha'', native to northwest Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Arge ...
''
*''Polygala rectipilis'' = ''Hebecarpa rectipilis
''Hebecarpa rectipilis'', synonym ''Polygala rectipilis'', common name New Mexico milkwort, is a plant native to one county in New Mexico and to northeast Mexico. The type specimen was collected near the Town of Hillsboro in Sierra County, at ...
''
*''Polygala subspinosa'' = ''Rhinotropis subspinosa
''Rhinotropis subspinosa'', synonym ''Polygala subspinosa'', is a species of flowering plant in the milkwort family known by the common name spiny milkwort. It is native to the southwestern United States, where it grows in desert and plateau hab ...
''
Hybrid
''Polygala'' × ''dalmaisiana'' (of garden origin)
Ecology
''Polygala'' 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.
The ...
e of some Lepidoptera
Lepidoptera ( ) is an order (biology), order of insects that includes butterfly, butterflies and moths (both are called lepidopterans). About 180,000 species of the Lepidoptera are described, in 126 Family (biology), families and 46 Taxonomic r ...
species including large grizzled skipper
The Large Grizzled skipper (''Pyrgus alveus'') is a species of skipper butterfly (family Hesperiidae). Description
This is a rather variable species with a wingspan of 22–32 mm (not always particularly "large") with several subspecies having ...
.
Cultivation
Some species are valued in cultivation. An evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...
shrub has gained the Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...
's Award of Garden Merit
The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions.
History
The Award of Garden Merit ...
under the name ''P.'' × ''dalmaisiana''.
References
{{Authority control
Fabales genera