''Polygala'' is a large

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 ...

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 on ...

. 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 (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

zones and the

tropics The tropics are the regions of Earth surrounding the equator, where the sun may shine directly overhead. This contrasts with the temperate or polar regions of Earth, where the Sun can never be directly overhead. This is because of Earth's ax ...

.''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 classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

"much milk", as the plant was thought to increase milk yields in cattle.

Description

As traditionally

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

, ''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 (band), a ...

and

perennial plant In horticulture, the term perennial (''wikt:per-#Prefix, per-'' + ''wikt:-ennial#Suffix, -ennial'', "through the year") is used to differentiate a plant from shorter-lived annual plant, annuals and biennial plant, biennials. It has thus been d ...

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 ...

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 ...

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, e.g., including only woody plants with secondary growth, only ...

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. ...

. The leaf blades are generally undivided and smooth-edged, and are alternately arranged in most species. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is 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 ...

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 Etymology The term ''sepalum'' ...

s on the sides, often called the "wings", and three smaller sepals behind. There are three

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

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 The following terms are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade is divided into two or more leaflets) ...

ood-like or helmet-shaped". The keel petal may have a beak or a fringe on the tip.

Stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s and

style Style, or styles may refer to: Film and television * ''Style'' (2001 film), a Hindi film starring Sharman Joshi, Riya Sen, Sahil Khan and Shilpi Mudgal * ''Style'' (2002 film), a Tamil drama film * ''Style'' (2004 film), a Burmese film * '' ...

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 (), also called 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 seed to the ova ...

. 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 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 1754. Phylogenetic studies showed that, as traditionally circumscribed, the genus was not

monophyletic In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria: # the grouping contains its own most recent co ...

. 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 purpose of classifying organisms that do not fit anywhere else. They are typically defined by e ...

"; 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

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 350Coelho, 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 725Lüdtke, 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 taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

'' accepted about 420 species in the genus ''Polygala''. These include: Polygala amara a1

Former species

*''Polygala acanthoclada'' = '' Rhinotropis acanthoclada'' *''Polygala africana'' = ''

Senega africana ''Senega africana'' is a species of flowering plant in the milkwort 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 ...

'' *''Polygala alba'' = ''

Senega alba ''Senega alba'', commonly called white milkwort, is a species of flowering plant in the milkwort family (Polygalaceae). Distribution It is native to North America, where it is found in Canada, Mexico, and the United States. In the United States, ...

'' *''Polygala ambigua'' Nutt. = '' Senega ambigua'' *''Polygala ambigua'' Torr. & A.Gray = ''

Senega nuttallii ''Senega nuttallii'' is a species of flowering plant in the milkwort family (Polygalaceae). It is endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country ...

'' *''Polygala boykinii'' = ''

Senega boykinii ''Senega boykinii'', known by the common name Boykin's milkwort, is a species of flowering plant. It grows to about 2 feet high and produces a spear of white flowers. It is a dicot in the family Polygalaceae The Polygalaceae or the milkwort fa ...

'' *''Polygala californica'' = '' Rhinotropis californica'' *''Polygala chamaebuxus'' = '' Polygaloides chamaebuxus'' *''Polygala cornuta'' = ''

Rhinotropis cornuta ''Rhinotropis'' is a small genus in the family Polygalaceae. It was separated as a genus from ''Polygala'' by J. Richard Abbott in 2011. It is native to the south and west of the United States (Arizona, California, Colorado, Nevada, New Mexico, T ...

'' *''Polygala cruciata'' = ''

Senega cruciata ''Senega cruciata'', commonly called drumheads milkwort, is a species of flowering plant in the milkwort family. It is native to eastern North America, where it is found in scattered localities, particularly around the Coastal Plain, the Great L ...

'' *''Polygala curtissii'' = '' Senega curtissii'' *''Polygala heterorhyncha'' = '' Rhinotropis heterorhyncha'' *''Polygala incarnata'' Aubl. = '' Senega adenophora'' *''Polygala incarnata'' L. = ''

Senega incarnata ''Senega'' is a genus of flowering plants in the milkwort family (Polygalaceae) native to the Americas, tropical and southern Africa, and Madagascar. It was resurrected from the genus ''Polygala'' in 2023. The North American species ''Senega offic ...

'' *''Polygala intermontana'' = '' Rhinotropis intermontana'' *''Polygala lewtonii'' = '' Senega lewtonii'' *''Polygala lutea'' = ''

Senega lutea ''Senega lutea'', commonly known as orange- or yellow milkwort, is a plant in the milkwort family (Polygalaceae) native to pine-barren depressions and swamps in coastal areas of the southern and eastern the United States. It was first described ...

'' *''Polygala macradenia'' = '' Hebecarpa macradenia'' *''Polygala nana'' = ''

Senega nana ''Senega nana'', commonly known as candyroot or low bachelors' buttons, is a small species of herbaceous plant native to the south-eastern United States. The root has a sweet liquorice flavor when it is chewed, but it is usually hidden undergroun ...

'' *''Polygala paucifolia'' = '' Polygaloides paucifolia'' *''Polygala poaya'' = ''

Senega poaya ''Senega poaya'' is a herbaceous species of plant native to South America. It is a perennial plant, becoming somewhat woody at the base. It grows to a clump of stems 8–50 cm tall. The root is sometimes used for local medicinal use. It is a ...

'' *''Polygala polygama'' = ''

Senega polygama ''Senega polygama'', the racemed milkwort, is a species of flowering plant in the family Polygalaceae, native to eastern Canada and the central and eastern United States. A biennial reaching , it has pink or purple flowers, and produces additiona ...

'' *''Polygala pterolopha'' = '' Monrosia pterolopha'' *''Polygala quitensis'' = ''

Senega quitensis ''Senega quitensis'' is a species of plant in the family Polygalaceae. It is endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zon ...

'' *''Polygala rectipilis'' = '' Hebecarpa rectipilis'' *''Polygala sanguinea'' L. = ''

Senega sanguinea ''Senega sanguinea'', commonly known as purple milkwort, field milkwort, or blood milkwort is an annual species of plant in the milkwort family (Polygalaceae). It is native to central and eastern North America. Description ''S. sanguinea'' grows ...

'' *''Polygala sanguinea'' Nutt. = ''

'' *''Polygala senega'' = ''

Senega officinalis ''Senega officinalis'' is a species of flowering plant in the milkwort family, Polygalaceae. It is native to North America, where it is found in southern Canada and the central and eastern United States.Senega smallii ''Senega smallii'', commonly known as tiny polygala and tiny milkwort, is a rare species of flowering plant in the milkwort family . It is endemic to Florida in the United States, where it is limited to the south-eastern coast of the peninsula. ...

'' *''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 (; : 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

large grizzled skipper The Large Grizzled skipper (''Pyrgus alveus'') is a species of skipper (butterfly), skipper butterfly (family Hesperiidae). Description This is a rather variable species with a wingspan of 22–32 mm (not always particularly "large") with severa ...

Cultivation

Some species are valued in cultivation. ''Polygala'' × ''dalmaisiana'', an

evergreen In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...

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 ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

References

{{Authority control Fabales genera