Polygonum
Encyclopedia
Polygonum is a genus
in the Polygonaceae
family. Common names include knotweed, knotgrass, bistort, tear-thumb, mile-a-minute, and several others. In the Middle English
glossary
of herbs "Alphita" (ca. 1400-1425), it was known as ars-smerte. There have been various opinions about how broadly the genus should be defined. For example, Buckwheat
has sometimes been included in the genus.
The genus primarily grows in northern temperate
regions. They vary widely from prostrate herbaceous
annual plant
s under 5 cm high, others erect herbaceous perennial plant
s growing to 3–4 m tall, and yet others perennial wood
y vine
s growing to 20–30 m high in tree
s. Several are aquatic, growing as floating plants in pond
s. The smooth-edged leaves
range from 1–30 cm long, and vary in shape between species from narrow lanceolate to oval, broad triangular, heart-shaped, or arrowhead forms. The stems are often reddish or red-speckled. The small flower
s are, pink, white, or greenish, forming in summer in dense clusters from the leaf joints or stem apices.
The genus name is from the Greek
poly, "many" and gonu, "knee" in reference to the swollen jointed stem.
Polygonum species are occasionally eaten by humans, and are used as food plants by the larva
e of some Lepidoptera
species - see list. Most species are considered weedy, especially in moist soils in the USA.
, Fallopia
and Persicaria
.
The genus Polygonella
has a number of morphological similarities with Polygonum, and some authors have included Polygonella in Polygonum.
Selected species include:
Reclassified as Fagopyrum
Reclassified as Fallopia
Reclassified as Persicaria
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
in the Polygonaceae
Polygonaceae
Polygonaceae is a family of flowering plants known informally as the "knotweed family" or "smartweed family"— "buckwheat family" in the United States. The name is based on the genus Polygonum and was first used by Antoine Laurent de Jussieu in 1789 in his book, Genera Plantarum. The name refers...
family. Common names include knotweed, knotgrass, bistort, tear-thumb, mile-a-minute, and several others. In the Middle English
Middle English
Middle English is the stage in the history of the English language during the High and Late Middle Ages, or roughly during the four centuries between the late 11th and the late 15th century....
glossary
Glossary
A glossary, also known as an idioticon, vocabulary, or clavis, is an alphabetical list of terms in a particular domain of knowledge with the definitions for those terms...
of herbs "Alphita" (ca. 1400-1425), it was known as ars-smerte. There have been various opinions about how broadly the genus should be defined. For example, Buckwheat
Buckwheat
Buckwheat refers to a variety of plants in the dicot family Polygonaceae: the Eurasian genus Fagopyrum, the North American genus Eriogonum, and the Northern Hemisphere genus Fallopia. Either of the latter two may be referred to as "wild buckwheat"...
has sometimes been included in the genus.
The genus primarily grows in northern temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
regions. They vary widely from prostrate herbaceous
Herbaceous
A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...
annual plant
Annual plant
An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...
s under 5 cm high, others erect herbaceous perennial plant
Perennial plant
A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...
s growing to 3–4 m tall, and yet others perennial wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
y vine
Vine
A vine in the narrowest sense is the grapevine , but more generally it can refer to any plant with a growth habit of trailing or scandent, that is to say climbing, stems or runners...
s growing to 20–30 m high in tree
Tree
A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...
s. Several are aquatic, growing as floating plants in pond
Pond
A pond is a body of standing water, either natural or man-made, that is usually smaller than a lake. A wide variety of man-made bodies of water are classified as ponds, including water gardens, water features and koi ponds; all designed for aesthetic ornamentation as landscape or architectural...
s. The smooth-edged leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
range from 1–30 cm long, and vary in shape between species from narrow lanceolate to oval, broad triangular, heart-shaped, or arrowhead forms. The stems are often reddish or red-speckled. The small flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
s are, pink, white, or greenish, forming in summer in dense clusters from the leaf joints or stem apices.
The genus name is from the Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
poly, "many" and gonu, "knee" in reference to the swollen jointed stem.
Polygonum species are occasionally eaten by humans, and are used as food plants by the larva
Larva
A larva 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...
e of some Lepidoptera
Lepidoptera
Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...
species - see list. Most species are considered weedy, especially in moist soils in the USA.
Distribution and uses
Several species can be eaten cooked, for example during famines. The variety Polygonum cognatum, known locally as "madimak", is regularly consumed in central parts of Turkey. In Chinese medicine, a Polygonum extract called Rèlínqīng Kēlì (热林清颗粒) is used to treat urinary tract infections.Species
Between 65 and 300 species are recognised, depending on the circumscription of the genus; some botanists divide the genus into several smaller genera, including FagopyrumFagopyrum
The genus Fagopyrum in the flowering plant family Polygonaceae contains 15 to 16 species of plants, including two important crop plants, the Buckwheat or Japanese Buckwheat Fagopyrum esculentum, and the Tartary Buckwheat Fagopyrum tataricum. They have similar uses, and are classed as pseudocereals,...
, Fallopia
Fallopia
Fallopia is a genus of about 12–15 species of flowering plants in the family Polygonaceae, often included in a wider treatment of the related genus Polygonum in the past. The genus is native to temperate and subtropical regions of the Northern Hemisphere...
and Persicaria
Persicaria
Persicaria is a genus of plants in the family Polygonaceae, collectively known as smartweeds or pinkweeds. The genus was formerly included in the genus Polygonum.The genus includes both annuals and perennials...
.
The genus Polygonella
Polygonella
Polygonella is a genus of flowering plants in the knotweed and smartweed family, Polygonaceae. Members of this genus are sometimes called jointweed or wireweed.-Selected species:...
has a number of morphological similarities with Polygonum, and some authors have included Polygonella in Polygonum.
Selected species include:
- Polygonum achoreum
- Polygonum acetosum
- Polygonum acuminata
- Polygonum acuminatum - tapertip smartweed
- Polygonum albanicumPolygonum albanicumPolygonum albanicum is a flowering herbaceous plant of the knotweed family. It is a trans-regional endemic species primarily found in Albania and recently in its neighboring countries.-History and distribution:...
- Polygonum alpestre
- Polygonum arenarium
- Polygonum arenastrumPolygonum arenastrumPolygonum arenastrum is a summer annual weed that is native to Europe and can be found on most continents as an introduced species and a common noxious weed...
– small-leaved knotgrass - Polygonum argyrocoleon
- Polygonum arifolium
- Polygonum avicularePolygonum avicularePolygonum aviculare or Common Knotgrass is a plant related to buckwheat and dock. It is also called birdweed, pigweed and lowgrass. It is an annual found in fields and wasteland, with white flowers from June to October....
– common knotgrass - Polygonum bellardii
- Polygonum bidwelliaePolygonum bidwelliaePolygonum bidwelliae is an uncommon species of flowering plant in the knotweed family known by the common name Bidwell's knotweed. The plant was named for American suffragist Annie Bidwell, based at the Bidwell Mansion in Chico, California, who collected the type specimen in Northern...
- Polygonum bistortoidesPolygonum bistortoidesPolygonum bistortoides , syn. Bistorta bistortoides, is a perennial herb in the genus Polygonum....
American bistort, western bistort, smokeweed or mountain meadow knotweed - Polygonum bolanderiPolygonum bolanderiPolygonum bolanderi is an uncommon species of flowering plant in the knotweed family known by the common name Bolander's knotweed.-Distribution:...
- Polygonum boreale
- Polygonum brasiliensis
- Polygonum bungeanum - Bunge's smartweed
- Polygonum buxiforme
- Polygonum caespitosumPolygonum caespitosumPolygonum caespitosum or Tufted Knotweed is a summer annual weed plant of the family Polygonaceae, native to eastern and central North America. The plant grows to 3.5 feet in height with elliptic to lanceolate leaves, usually 20-75 mm long...
- Polygonum californicumPolygonum californicumPolygonum californicum is a species of flowering plant in the knotweed family known by the common name California knotweed. It is native to the west coast of the United States from Washington to central California, where it can be found in many types of open habitat.-Description:Polygonum...
– California knotweed - Polygonum careyi - Carey's smartweed
- Polygonum cascadense
- Polygonum caurianum
- Polygonum chinensePolygonum chinensePolygonum chinense is a plant species from the Polygonaceae family. It is one of the most common plants you can find in Malaysia and for the old folks they use it for regenerating the health and manly hood....
- Polygonum coccineumPolygonum coccineumPolygonum coccineum, commonly called water smartweed, is a perennial herb in the genus Polygonum....
- Polygonum cognatum – Indian knotgrass
- Polygonum davisiaePolygonum davisiaePolygonum davisiae is a species of flowering plant in the knotweed family known by the common name Davis' knotweed.-Distribution:It is native to the western United States from Washington and Idaho to the Sierra Nevada, where it grows in high mountain habitat, such as talus and...
- Polygonum densiflorum
- Polygonum dibotrys
- Polygonum douglasiiPolygonum douglasiiPolygonum douglasii is a species of flowering plant in the knotweed family known by the common name Douglas's knotweed. It is native to much of northern and western North America, where it can be found in many types of habitat, including disturbed areas.This plant species is known as a species...
– Douglas' knotweed - Polygonum erectumPolygonum erectumPolygonum erectum is an annual plant species with upright or ascending stems. It is a common weed in disturbed locations with dry soils in the North Eastern USA where it is called Erect knotweed.-Description:...
- Polygonum flaccidum – (Meisn.Carl MeissnerCarl Daniel Friedrich Meissner was a Swiss botanist.Born in Bern, Switzerland on 1 November 1800, he was christened Meisner but later changed the spelling of his name to Meissner. For most of his 40 year career he was Professor of Botany at University of Basel...
) - Polygonum foliosum
- Polygonum forrestii
- Polygonum fowleri
- Polygonum franktonii
- Polygonum glaucum
- Polygonum griffithii
- Polygonum herniarioides
- Polygonum heterosepalum – dwarf desert knotweed
- Polygonum hickmaniiPolygonum hickmaniiPolygonum hickmanii is a rare species of flowering plant in the buckwheat family known by the common names Scotts Valley polygonum and Hickman's knotweed. It is endemic to Santa Cruz County, California, where it is known from only two occurrences in the Scotts Valley...
- Polygonum hirsutum
- Polygonum hongkongensis
- Polygonum hudsonianum
- Polygonum hydropiperoidesPolygonum hydropiperoidesPolygonum hydropiperoides is a species of flowering plant in the knotweed family known by the common name swamp smartweed. It is native to much of North America where it grows in moist and wet habitats, and is sometimes semi-aquatic....
- swamp smartweed - Polygonum lacerum
- Polygonum lanigerum
- Polygonum marinensePolygonum marinensePolygonum marinense is a species of flowering plant in the knotweed family known by the common name Marin knotweed. It is endemic to California, where it is known from just a few locations around the northern San Francisco Bay Area....
- Polygonum maritimum – sea knotgrass
- Polygonum meisneranum
- Polygonum meisnerianum
- Polygonum minimumPolygonum minimumPolygonum minimum is a species of flowering plant in the knotweed family known by the common name broadleaf knotweed. It is native to much of western North America where it can be found in mountainous regions...
– broadleaf knotweed - Polygonum multiflorum
- Polygonum newberryi - Newberry knotweed
- Polygonum oxyspermum – Ray's knotgrass
- Polygonum paronychiaPolygonum paronychiaPolygonum paronychia is a species of flowering plant in the knotweed family known by the common names dune knotweed, black knotweed, and beach knotweed...
- Polygonum paronychioides
- Polygonum parryiPolygonum parryiPolygonum parryi is a species of flowering plant in the knotweed family known by the common name Parry's knotweed. It is native to the western United States from Washington to California, where it grows in several types of moist, open habitat in mountainous and coastal areas.-Description:It is a...
- Polygonum patulum - Bellard's smartweed
- Polygonum perfoliatum – mile-a-minute weed
- Polygonum phytolaccifoliumPolygonum phytolaccifoliumPolygonum phytolaccifolium is a species of flowering plant in the knotweed family known by the common name poke knotweed. It is native to the western United States, where it grows in subalpine and alpine climates in mountains, rocky plateaus, and other regions.It is a sturdy perennial herb...
- Polygonum plebeium
- Polygonum polycnemoides
- Polygonum polycnenoides
- Polygonum polygaloidesPolygonum polygaloidesPolygonum polygaloides is a species of flowering plant in the knotweed family known by the common names milkwort knotweed and polygala knotweed. It is native to much of western North America, where it can be found in many types of moist habitat...
- Polygonum polystachyumPolygonum polystachyumPolygonum polystachyum is a species of flowering plant in the knotweed family known by the common names Himalayan knotweed and cultivated knotweed....
- Polygonum punctatum - dotted smartweed
- Polygonum raii = Polygonum oxyspermum
- Polygonum ramosissimumPolygonum ramosissimumPolygonum ramosissimum is a herbaceous annual plant species native from most of North America, were it is commonly called Bushy knotweed.-Description:...
- Polygonum robustius - stout smartweed
- Polygonum rurivagum
- Polygonum salicifolium
- Polygonum scoparium
- Polygonum segetum - field smartweed
- Polygonum setaceum - bog smartweed
- Polygonum shastensePolygonum shastensePolygonum shastense is a species of flowering plant in the knotweed family known by the common name Shasta knotweed. It is native to sections of Oregon, Nevada, and California, where it grows in rocky and gravelly mountainous habitat.-Description:...
- Polygonum striatulum
- Polygonum tenue
Reclassified as FagopyrumFagopyrumThe genus Fagopyrum in the flowering plant family Polygonaceae contains 15 to 16 species of plants, including two important crop plants, the Buckwheat or Japanese Buckwheat Fagopyrum esculentum, and the Tartary Buckwheat Fagopyrum tataricum. They have similar uses, and are classed as pseudocereals,...
- Polygonum fagopyrum (Fagopyrum esculentum) – buckwheatBuckwheatBuckwheat refers to a variety of plants in the dicot family Polygonaceae: the Eurasian genus Fagopyrum, the North American genus Eriogonum, and the Northern Hemisphere genus Fallopia. Either of the latter two may be referred to as "wild buckwheat"...
Reclassified as FallopiaFallopiaFallopia is a genus of about 12–15 species of flowering plants in the family Polygonaceae, often included in a wider treatment of the related genus Polygonum in the past. The genus is native to temperate and subtropical regions of the Northern Hemisphere...
- Polygonum aubertii = Polygonum baldschuanicum
- Polygonum baldschuanicum (Fallopia baldschuanicaFallopia baldschuanicaFallopia baldschuanica is a species of flowering plant in the knotweed family known by several common names, including Russian vine, Bukhara fleeceflower, Chinese fleecevine, mile-a-minute and silver lace vine...
) (Fallopia aubertii, Bilderdykia aubertii, Bilderdykia balschuanicum) – Russian vine - Polygonum cilinode (Fallopia cilinodis, Bilderdykia cilinodis) – fringed black bindweed, mountain bindweed
- Polygonum convolvulus (Fallopia convolvulus) – Black Bindweed, wild buckwheat
- Polygonum cuspidatum = Polygonum japonicum - Japanese knotweedJapanese knotweedJapanese Knotweed is a large, herbaceous perennial plant, native to eastern Asia in Japan, China and Korea...
- Polygonum dumetorum (Fallopia dumetorum) – copse bindweed
- Polygonum japonicum (Fallopia japonica, Reynoutria japonica) – Japanese knotweedJapanese knotweedJapanese Knotweed is a large, herbaceous perennial plant, native to eastern Asia in Japan, China and Korea...
- Polygonum multiflorum (Fallopia multifloraFallopia multifloraFallopia multiflora is a species of Fallopia native to central and southern China.It is a herbaceous perennial vine growing to 2–4 m tall from a woody tuber. The leaves are 3–7 cm long and 2–5 cm broad, broad arrowhead-shaped, with an entire margin...
) - Polygonum sachalinense (Fallopia sachalinensisFallopia sachalinensisFallopia sachalinensis Fallopia sachalinensis Fallopia sachalinensis (Giant Knotweed or Sakhalin Knotweed Japanese オオイタドリ ooitadori, Russian Горец сахалинский, Гречиха сахалинская; syn...
, Reynoutria sachalinensis) – giant knotweed - Polygonum scandens (Fallopia scandens)
Reclassified as PersicariaPersicariaPersicaria is a genus of plants in the family Polygonaceae, collectively known as smartweeds or pinkweeds. The genus was formerly included in the genus Polygonum.The genus includes both annuals and perennials...
- Polygonum affine (Persicaria affinisPersicaria affinisPersicaria affinis is an ornamental plant of Persicaria genus in Polygonaceae family.-External links:*...
) - Polygonum alatum (Persicaria alata)
- Polygonum alpinum – alpine knotweed (Persicaria alpina)
- Polygonum amphibium – amphibious bistort, longroot smartweed, water smartweed, (Persicaria amphibiaPersicaria amphibiaPersicaria amphibia is a species of flowering plant in the knotweed family known by several common names, including water knotweed, water smartweed, and amphibious bistort. It is native to much of North America and Eurasia, but it is known on most continents as an introduced species and sometimes...
) - Polygonum amplexicaule (Persicaria amplexicaulis)
- Polygonum bistorta – bistort (Persicaria bistortaPersicaria bistortaPersicaria bistorta is a herbaceous flowering plant found throughout Europe. The generic placement of this species is in flux. While treated here as in Persicaria, it has also been placed in Polygonum or Bistorta.The Latin name "bistorta" refers to the twisted appearance of the root...
) - Polygonum campanulatum – lesser knotweed, bellflower smartweed, (Persicaria campanulata) (Reynoutria campanulatum)
- Polygonum capitatum - pinkhead smartweed, (Persicaria capitataPersicaria capitataPersicaria capitata is an ornamental plant of the Persicaria genus in the Polygonaceae family. The spikes are 5-10mm long and 5-7mm in diameter.-Description:...
) - Polygonum emodi (Persicaria emodi)
- Polygonum filiforme (Persicaria virginianaPersicaria virginianaJumpseed is a Persicaria. They can grow in dry, shady areas.It blooms in midsummer to late summer/early fall. It has a stalk of small white flowers.-Cultivation:...
) - Polygonum hydropiper – water-pepperWater-pepperWater-pepper or Water pepper is a plant of the family Polygonaceae. It grows in damp places and shallow water. It is a cosmopolitan plant, found in Australia, New Zealand, temperate Asia, Europe, and North America...
(Persicaria hydropiper) - Polygonum lapathifolium – pale persicariaPale PersicariaPale Persicaria is a plant of the family Polygonaceae. It is closely related to Redshank and as such is considered a weed in Britain and Europe....
or nodding smartweed (Persicaria lapathifolia) - Polygonum longisetum (Persicaria longiseta)
- Polygonum macrophyllum (Persicaria macrophylla)
- Polygonum milletii (Persicaria milletii)
- Polygonum minus – small water-pepper (Persicaria minor)
- Polygonum mite – tasteless water-pepper (Persicaria mitis, Persicaria laxiflora)
- Polygonum molle (Persicaria mollis)
- Polygonum nepalense (Persicaria nepalensis)
- Polygonum odoratum – Vietnamese corianderVietnamese corianderPersicaria odorata, the Vietnamese coriander, is an herb whose leaves are used in Southeast Asian cooking. Other English names for the herb include Vietnamese mint, Vietnamese cilantro, Cambodian mint and hot mint. The Vietnamese name is rau răm, while in Malaysia and Singapore it is called daun...
(Persicaria odorata) - Polygonum orientale (Persicaria orientalis)
- Polygonum pensylvanicum – Pennsylvania smartweed or pink knotweed or pinkweed (Persicaria pensylvanica)
- Polygonum persicaria – redshankRedshank (plant)The Redshank is a perennial plant from the Knotweed family Polygonaceae. It is also called Persicaria, Redleg, Lady's-thumb, Spotted Ladysthumb, Gambetta, and Adam's Plaster in Newfoundland...
or persicaria or lady's thumb (Persicaria maculosa) - Polygonum polystachyum = Polygonum wallichii
- Polygonum runciforme (Persicaria runcinata)
- Polygonum sagittatum – arrowleaf tearthumb, American tear-thumb or scratchgrass (Persicaria sagittata)
- Polygonum tenuicaule (Persicaria tenuicaulis)
- Polygonum tinctorium (Persicaria tinctoria)
- Polygonum vaccinifolium (Persicaria vaccinifolia)
- Polygonum virginianum (Persicaria virginianaPersicaria virginianaJumpseed is a Persicaria. They can grow in dry, shady areas.It blooms in midsummer to late summer/early fall. It has a stalk of small white flowers.-Cultivation:...
) - Polygonum viviparum – alpine bistortAlpine BistortPolygonum viviparum , commonly known as Alpine Bistort, is common all over the high Arctic. It stretches further south in high mountainous areas like the Alps, Carpathians, Pyrenees, Caucasus and the Tibetan Plateau.It grows to 5-15 cm tall with a thick rootstock...
(Persicaria vivipara) - Polygonum wallichii – Himalayan knotweed (Persicaria wallichii)
- Polygonum weyrichii (Persicaria weyrichii)
External links
- http://internt.nhm.ac.uk/jdsml/nature-online/nature-navigator/Website of the Natural History MuseumNatural History MuseumThe Natural History Museum is one of three large museums on Exhibition Road, South Kensington, London, England . Its main frontage is on Cromwell Road...
, London] - http://www.rhs.org.uk/RHSPlantFinder/plantfinder.aspPlant Finder section of the Royal Horticultural SocietyRoyal Horticultural SocietyThe Royal Horticultural Society was founded in 1804 in London, England as the Horticultural Society of London, and gained its present name in a Royal Charter granted in 1861 by Prince Albert...
's website] - Flora of Northern Ireland