Polygala

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Polygala
Polygala vulgaris 290504.jpg
Polygala vulgaris
Scientific classification Red Pencil Icon.png
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Fabales
Family: Polygalaceae
Tribe: Polygaleae
Genus: Polygala
L.
Type species
Polygala vulgaris
L.
Species

See text

Synonyms
  • MonrosiaGrondona 1949
  • PilostaxisRaf.
  • TriclispermaNieuwl.

Polygala is a large genus of flowering plants belonging to the family Polygalaceae. They are commonly known as milkworts or snakeroots. The genus is distributed widely throughout much of the world [1] in temperate zones and the tropics. [2] The genus name Polygala comes from the ancient Greek "much milk", as the plant was thought to increase milk yields in cattle. [3]

Contents

Description

As traditionally circumscribed, Polygala includes annual and perennial plants, shrubs, vines, and trees. [1] The roots often have a scent reminiscent of wintergreen. [2] The leaf blades are generally undivided and smooth-edged, and are alternately arranged in most species. The inflorescence is a raceme or spikelike array of several flowers; the occasional species bears solitary flowers. [2] The flower is bilateral in shape, with two large petal-like sepals on the sides, often called the "wings", [2] and three smaller sepals behind. There are three petals 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 [hood-like], or helmet-shaped". [1] The keel petal may have a beak or a fringe on the tip. [2] Stamens and style are within the curve of the keel petal. The fruit is a capsule, sometimes winged. It contains two seeds, [1] which are usually black, hairy and tipped with a large white aril. [2] No members of this genus are known to form nitrogen-fixing nodules. [4]

Taxonomy

The genus Polygala was first described by Carl Linnaeus in 1754. Phylogenetic studies showed that, as traditionally circumscribed, the genus was not monophyletic. It had become a "wastebasket taxon"; almost all species with a flower apparently similar to those of the Papilionoideae – two petaloid lateral sepals 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. [5]

Species

Partly because of differing circumscriptions, the reported number of valid species in the genus varies from about 350 [6] [7] to 500 [1] [2] to 725 [8] or 730. [9] The Americas have the most species, especially South America, [9] with Africa second in diversity and Asia third. [8] As of April 2020, Plants of the World Online accepted about 660 species in the genus Polygala. These include: [10]

Polygala amara Polygala amara a1.jpg
Polygala amara
Polygala lutea Bog Batchelors Button (5385569343).jpg
Polygala lutea
Polygala myrtifolia Polygala myrtifolia (2921770836).jpg
Polygala myrtifolia
Polygala nana Polygalanana.jpg
Polygala nana
Polygala poaya Flickr - Joao de Deus Medeiros - Polygala poaya.jpg
Polygala poaya

Species now placed in other genera:

Hybrid

Polygala × dalmaisiana (of garden origin)

Ecology

Polygala species are used as food plants by the larvae of some Lepidoptera species including large grizzled skipper.

Cultivation

Some species are valued in cultivation. An evergreen shrub has gained the Royal Horticultural Society's Award of Garden Merit under the name P. × dalmaisiana. [12]

Related Research Articles

<span class="mw-page-title-main">Polygalaceae</span> Family of flowering plants

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 genus, Polygala, the milkworts.

<i>Polygala vulgaris</i> Species of flowering plant

Polygala vulgaris, known as the common milkwort, is a herbaceous perennial plant of the genus Polygala in the family Polygalaceae.

<i>Polygaloides paucifolia</i> Species of flowering plant

Polygaloides paucifolia, synonym Polygala paucifolia, known as gaywings or fringed polygala, is a perennial plant of the family Polygalaceae.

<i>Polygaloides chamaebuxus</i> Species of shrub

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 white to yellow, sometimes pinkish or purple. The keel petals are bright yellow, aging to brownish-red or purple. It is native to the Alps and the mountains of west-central Europe. It was known to be grown in cultivation in about 1658 and was illustrated by Carolus Clusius. It has been given the Royal Horticultural Society's Award of Garden Merit.

<i>Comesperma</i> Genus of flowering plants

Comesperma is a genus of shrubs, herbs and lianas in the family Polygalaceae. The genus is endemic to Australia. It was defined by the French botanist Jacques Labillardière in his 1806 work Novae Hollandiae Plantarum Specimen. The genus name is derived from the Ancient Greek words come ("hair") and sperma ("seed"), and relates to the seeds bearing tufts of hair. The genus is distributed over southern Australia, particularly in the southwest of Western Australia, where 19 species are found. 24 species have been described.

<i>Rhinotropis acanthoclada</i> Species of flowering plant

Rhinotropis acanthoclada, synonym Polygala acanthoclada, is a species of flowering plant in the milkwort family known by the common names desert polygala and thorn milkwort. It is native to the desert woodlands of the southwestern United States from Utah to the Mojave Desert. It is a small, bushy shrub spreading or growing erect and approaching one meter in maximum height. It is hairy in texture, the youngest twigs hairiest with a feltlike coat of short, whitish fibers. The lance-shaped or oval leaves are up to 2.5 centimeters long. Some of the twigs narrow to spines at the tips, especially in the inflorescences. The flowers are solitary or in clusters of up to 15. Each flower has five sepals, the lateral two white in color and spreading out like wings. The middle petal is keeled, with a flat tip protruding. The fruit is a capsule about half a centimeter long.

<i>Rhinotropis californica</i> Species of flowering plant

Rhinotropis californica, synonym Polygala californica, is a species of flowering plant in the milkwort family known by the common name California milkwort. It is native to southwestern Oregon and northern and central California, where it grows in the coastal mountain ranges in local habitat types such as chaparral and forest. It is a perennial herb producing spreading stems, generally decumbent in form, up to about 35 centimeters in maximum length, lined with narrow oval leaves each a few centimeter long. The upper inflorescences produce several open flowers, and there may be some closed, cleistogamous flowers lower on the plant. The open flowers have pink or white winglike lateral sepals with hairy edges. The petals are similar in color, the central one tipped with a white or yellow beak. The fruit is a flattened green capsule up to a centimeter long containing hairy seeds.

<i>Rhinotropis cornuta</i> Species of flowering plant

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 it grows in local habitat types such as chaparral and forest. It is a rhizomatous perennial herb or shrub known to exceed 2 meters in maximum height, spreading or growing erect. The leaves are linear, lance-shaped, or narrowly oval, up to 6.5 centimeters long, and widely spaced along the branches. The inflorescence is a short array of flowers varying in color from greenish or yellowish white to pink. Each has two winglike lateral sepals, and the keeled central petal is tipped with a short beak. The fruit is a brownish flattened capsule.

Rhinotropis intermontana, synonym Polygala intermontana, is a species of flowering plant in the milkwort family known by the common name intermountain milkwort. It is native to the southwestern United States from Utah to northern Arizona and far eastern California, where it grows in desert scrub and woodland habitat. It is a small shrub growing erect or forming tangled, mats of thorny, highly branched stems. The stems are hairy in texture with white fibers. The sparse leaves are linear to oval in shape. The inflorescence bears one to seven flowers, each just a few millimeters in length. The flower has a winglike pair of greenish or whitish sepals and a keeled central petal.

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 habitat. It is a perennial herb or small shrub growing in a clump no more than 25 centimeters tall. The stems have woody bases and green, thorn-tipped branches. The leaves are up to 3 centimeters in length and generally oval in shape. The flowers have winglike pairs of bright pink sepals and the keeled central petal is tipped with a yellowish beak, sometimes fringed at the tip.

<i>Polygala lewtonii</i> Species of flowering plant

Polygala lewtonii is a rare species of flowering plant in the milkwort family known by the common name Lewton's polygala, or Lewton's milkwort. It is endemic to Florida in the United States, where it is limited to the central ridge of the peninsula. There are about 49 occurrences of the plant remaining. Most occurrences contain very few plants. The species is threatened by the loss and degradation of its habitat. This is a federally listed endangered species of the United States.

<i>Polygala senega</i> Species of flowering plant

Polygala senega is a species of flowering plant in the milkwort family, Polygalaceae. It is native to North America, where it is distributed in southern Canada and the central and eastern United States. Its common names include Seneca snakeroot, senega snakeroot, senegaroot, rattlesnake root, and mountain flax. Its species name honors the Seneca people, a Native American group who used the plant to treat snakebite.

<i>Polygala myrtifolia</i> Species of shrub

Polygala myrtifolia, the myrtle-leaf milkwort, is an evergreen 2-4m tall South African shrub or small tree found along the southern and south-eastern coasts, from near Clanwilliam in the Western Cape to KwaZulu-Natal. It is a fast-growing pioneer plant, a typical fynbos component, and may be found on dunes, rocky places, along forest margins, beside streams, and in open grassland. It belongs to the milkwort family of Polygalaceae.

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 an elevation of 1065 m.

<i>Hebecarpa macradenia</i> Species of flowering plant

Hebecarpa macradenia, synonym Polygala macradenia, the glandleaf milkwort, is a subshrub in the milkwort family (Polygalaceae) found in the Arizona Uplands of the Sonoran Desert. Its "odd" flowers are said to be "spectacularly beautiful" when viewed with a hand lens.

<i>Polygala alba</i> Species of flowering plant

Polygala alba, commonly called white milkwort, is a species of flowering plant in the milkwort family (Polygalaceae).

<i>Rhinotropis</i> Genus of flowering plants

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 and to Mexico.

<i>Hebecarpa</i> Genus of flowering plants

Hebecarpa is a genus of flowering plants belonging to the family Polygalaceae. Species are found from the southern United States through Mexico and Central America to western South America.

<i>Muraltia heisteria</i> Plant species in the family Polygalaceae

Muraltia heisteria is a shrub in the milkwort family (Polygalaceae) which is native to South Africa and is cultivated in Australia. It was first described in 1753 by Carl Linnaeus.

Gymnospora is a genus of plants in the milkwort family (Polygalaceae) which is endemic to Brazil. It was first described as a subgenus of Polygala by Robert Chodat in 1891. It was separated into its own genera in 2013. Their flowers are 6 to 10 millimetres long and its pedicels are 2 to 8 millimetres long.

References

  1. 1 2 3 4 5 Polygala. Flora of China.
  2. 1 2 3 4 5 6 7 Polygala. The Jepson eFlora 2013.
  3. Coombes, A. J. (2012). The A to Z of Plant Names . USA: Timber Press. pp.  312. ISBN   9781604691962.
  4. Dilworth, M. J. (2008). Nitrogen-fixing leguminous symbioses (in Spanish). Dordrecht: Springer. ISBN   978-1-4020-3548-7. OCLC   226076050.
  5. Abbott, J. Richard (2011). "Notes on the disintegration of Polygala (Polygalaceae), with four new genera for the Flora of North America". Journal of the Botanical Research Institute of Texas. 5 (1): 125–137. JSTOR   41972495.
  6. Coelho, V. P. D. M., et al. (2008). Flora of Paraíba, Brazil: Polygala L.(Polygalaceae). Acta Botânica Brasilica 22(1), 225-39. (Portuguese)
  7. Coelho, V. P. D. M., et al. (2008). Flora of Paraíba, Brazil: Polygala L.(Polygalaceae). Acta Botânica Brasilica 22(1), 225-39. (Portuguese)
  8. 1 2 Lüdtke, R., et al. (2013). The genus Polygala L.(Polygalaceae) in Southern Brazil. Hoehnea 40(1), 1-50. (Portuguese)
  9. 1 2 Pastore, J. F. B. and T. B. Cavalcanti. (2008). A New Species of Polygala (Polygalaceae) from Brazil. Novon 18(1), 90-93.
  10. "Polygala Tourn. ex L.", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2020-04-13
  11. Dickinson, T., et al. (2004). ROM Field Guide to Wildflowers of Ontario. Royal Ontario Museum, Toronto. McClelland and Stewart Ltd. p 336.
  12. "RHS Plant Selector - Polygala × dalmaisiana" . Retrieved 13 April 2020.