The Polygonaceae are a

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

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 known informally as the knotweed family or smartweed—buckwheat family in the United States. The name is

based Brandon Christopher McCartney (born August 17, 1989), professionally known as Lil B and as his alter ego The BasedGod, is an American rapper. Lil B has recorded both solo and with Bay Area group The Pack. His solo work spans several genres, i ...

on the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

'' Polygonum'', and was first used by Antoine Laurent de Jussieu in 1789 in his book, ''Genera Plantarum''.Antoine Laurent de Jussieu. 1789. ''Genera plantarum: secundum ordines naturales disposita, juxta methodum in Horto regio parisiensi exaratam''. page 82. Herrisant and Barrois: Paris, France. (see ''External links'' below) The name may refer to the many swollen nodes the stems of some species have, being derived from

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

, ''poly'' meaning 'many' and ''gony'' meaning 'knee' or 'joint'. Alternatively, it may have a different derivation, meaning 'many seeds'. The Polygonaceae comprise about 1200

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

David J. Mabberley. 2008. ''Mabberley's Plant-Book'' third edition (2008). Cambridge University Press: UK. distributed into about 48 genera. The largest genera are ''

Eriogonum ''Eriogonum'' is a genus of flowering plants in the family Polygonaceae. The genus is found in North America and is known as wild buckwheat. This is a highly species-rich genus, and indications are that active speciation is continuing. It incl ...

'' (240 species), '' Rumex'' (200 species), ''

Coccoloba ''Coccoloba'' is a genus of about 120–150 species of flowering plants in the family Polygonaceae, which is native to the Neotropics. There is no overall English name for the genus, although many of the individual species have widely used common ...

'' (120 species), ''

Persicaria ''Persicaria'' is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds.Calligonum ''Calligonum'' is a genus of plants in the family Polygonaceae with about 80 species across the Mediterranean Sea region, Asia and North America. Description Plants of the genus ''Calligonum'' are shrubs, diffusely but irregularly branched, wi ...

'' (80 species).Craig C. Freeman and James L. Reveal. 2005. "Polygonaceae" pages 216-601. In: Flora of North America Editorial Committee (editors). ''Flora of North America'' vol. 5. Oxford University Press: New York, NY, USA. (see ''External links'' below)John Brandbyge. 1993. "Polygonaceae". pages 531-544. In: Klaus Kubitzki (editor); Jens G. Rohwer, and Volker Bittrich (volume editors). ''The Families and Genera of Vascular Plants'' volume II. Springer-Verlag: Berlin; Heidelberg, Germany (Berlin) (New York) The family is present worldwide, but is most diverse in the

North Temperate Zone 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 ...

. Several species are cultivated as

ornamentals Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...

Anthony Huxley Anthony Julian Huxley (2 December 1920 – 26 December 1992) was a British botanist. He edited ''Amateur Gardening'' from 1967 to 1971, and was vice-president of the Royal Horticultural Society in 1991. He was the son of Julian Huxley. He was ...

, Mark Griffiths, and Margot Levy (1992). ''The New Royal Horticultural Society Dictionary of Gardening''. The Macmillan Press,Limited: London. The Stockton Press: New York. (set). A few species of ''

Triplaris ''Triplaris'' is a genus of plants in the family Polygonaceae. Ant tree is a common name for plants in this genus. The species are variously distributed in the Americas. Some species are used for lumber. They are dioecious pioneer species. Spe ...

'' provide

lumber Lumber is wood that has been processed into dimensional lumber, including beams and planks or boards, a stage in the process of wood production. Lumber is mainly used for construction framing, as well as finishing (floors, wall panels, wi ...

. The fruit of the sea grape (''

Coccoloba uvifera ''Coccoloba uvifera'' is a species of flowering plant in the buckwheat family, Polygonaceae, that is native to coastal beaches throughout tropical America and the Caribbean, including southern Florida, the Bahamas, the Greater and Lesser Antille ...

'') is eaten, and in

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

, jelly is made from it and sold commercially.George W. Staples and Derral R. Herbst "A Tropical Garden Flora" Bishop Museum Press: Honolulu, Hawaii, USA. (2005) The seeds of two species of ''

Fagopyrum The genus ''Fagopyrum'' is in the flowering plant family Polygonaceae. It includes some important food plants, such as '' F. esculentum'' (buckwheat) and '' F. tataricum'' (Tartary buckwheat). The genus is native to the Indian subcontin ...

'', known as

buckwheat Buckwheat (''Fagopyrum esculentum''), or common buckwheat, is a flowering plant in the knotweed family Polygonaceae cultivated for its grain-like seeds and as a cover crop. The name "buckwheat" is used for several other species, such as ''Fagopy ...

, are eaten in the form of groats or used to make a flour. The petioles of rhubarb (''

Rheum Rheum (; from Greek: ῥεῦμα ''rheuma'' 'a flowing, rheum') is a thin mucus naturally discharged from the eyes, nose, or mouth, often during sleep (cf. mucopurulent discharge).Amodio, Aime"Where Do Eye Boogers Come From?" Families.com bl ...

rhabarbarum'' and hybrids) are a food item. The leaves of the common sorrel ('' Rumex acetosa'') are eaten in

salad A salad is a dish consisting of mixed, mostly natural ingredients with at least one raw ingredient. They are typically served at room temperature or chilled, though some can be served warm. Condiments and salad dressings, which exist in a va ...

s or as a

leaf vegetable Leaf vegetables, also called leafy greens, pot herbs, vegetable greens, or simply greens, are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. Leaf vegetables eaten raw in a salad can be called salad gre ...

.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Books: Ontario, Canada. (2007). . Polygonaceae contain some of the most prolific weeds, including species of ''Persicaria, Rumex'' and ''Polygonum'', such as Japanese knotweed.

Taxonomy

Polygonaceae are very well-defined and have long been universally recognized. In the APG III system, the family is placed in the order

Caryophyllales Caryophyllales ( ) is a diverse and heterogeneous order of flowering plants that includes the cacti, carnations, amaranths, ice plants, beets, and many carnivorous plants. Many members are succulent, having fleshy stems or leaves. The betalai ...

. Within the order, it lies outside of the large clade known as the core Caryophyllales. It is

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a family, familial relationship, it is sometimes used endearingly to r ...

to the family

Plumbaginaceae Plumbaginaceae is a family of flowering plants, with a cosmopolitan distribution. The family is sometimes referred to as the leadwort family or the plumbago family. Most species in this family are perennial herbaceous plants, but a few grow ...

, which it does not resemble morphologically.Peter F. Stevens. 2001 onwards. Angiosperm Phylogeny Website At: Missouri Botanical Garden Website. (see ''External links'' below). Polygonum plebeium W IMG 0462

The last comprehensive revision of the family was published in 1993 by John Brandbyge as part of ''The Families and Genera of Vascular Plants''. Brandbyge followed earlier systems of plant classification in dividing Polygonaceae into two subfamilies, Eriogonoideae and

Polygonoideae Polygonoideae is a subfamily of plants in the family Polygonaceae. It includes a number of plants that can be highly invasive, such as Japanese knotweed, ''Reynoutria japonica'', and its hybrid with '' R. sachalinensis'', ''R.'' × ''bohemica ...

. Since 1993, the circumscriptions of these two subfamilies have been changed in light of

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

studies of DNA sequences. Genera related to ''Coccoloba'' and ''Triplaris'' were moved from Polygonoideae to Eriogonoideae. The genus ''Symmeria'' does not belong to either of these subfamilies because it is sister to the rest of the family. ''Afrobrunnichia'' might constitute a new subfamily as well. Brandbyge wrote descriptions for 43 genera of Polygonaceae in 1993. Since then, a few more genera have been erected, and some segregates of ''Brunnichia'', ''Eriogonum'', and ''Persicaria'' have been given generic

status Status (Latin plural: ''statūs''), is a state, condition, or situation, and may refer to: * Status (law) ** City status ** Legal status, in law ** Political status, in international law ** Small entity status, in patent law ** Status confere ...

in major works.Anjen Li, Bojian Bao, Alisa E. Grabovskaya-Borodina, Suk-pyo Hong, John McNeill, Sergei L. Mosyakin, Hideaki Ohba, and Chong-wook Park. 2003. "Polygonaceae" pages 277-350. In: Zhengyi Wu, Peter H. Raven, and Deyuan Hong (editors). ''Flora of China'' volume 5. Science Press: Beijing, China; Missouri Botanical Garden Press: St. Louis, Missouri, USA. Some of the genera were found not to be monophyletic and their limits have been revised. These include ''Ruprechtia'', ''Eriogonum'', ''Chorizanthe'', ''Persicaria'', ''Aconogonon'', ''Polygonum'', ''Fallopia'', and ''Muehlenbeckia''.

Description

Most Polygonaceae are

perennial 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 wid ...

herbaceous plants with swollen nodes, but

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, shrubs and

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 themsel ...

s are also present. The leaves of Polygonaceae are simple, and arranged alternately on the stems. Each leaf has a peculiar pair of fused, sheathing

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole). Stipules are considered part of the anatomy of the leaf of a typical flowering plant, although in many speci ...

s known as an

ochrea An ochrea (Latin ''ocrea'', greave or protective legging), also spelled ocrea, is a plant structure formed of stipules fused into a sheath surrounding the stem, and is typically found in the Polygonaceae The Polygonaceae are a family of flow ...

. Those species that do not have the nodal ochrea can be identified by their possession of involucrate flower heads. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

s are normally bisexual, small, and

actinomorphic Floral symmetry describes whether, and how, a flower, in particular its perianth, can be divided into two or more identical or mirror-image parts. Uncommonly, flowers may have no axis of symmetry at all, typically because their parts are spirall ...

, with a perianth of three to six

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 coine ...

s. After

flowering A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...

, the sepals often become thickened and enlarged around the developing

fruit In botany, a fruit is the seed-bearing structure in flowering plants that is formed from the ovary after flowering. Fruits are the means by which flowering plants (also known as angiosperms) disseminate their seeds. Edible fruits in particu ...

. Flowers lack a corolla and in some, the sepals are petal-like and colorful. The androecium is composed of three to eight stamens that are normally free or

united United may refer to: Places * United, Pennsylvania, an unincorporated community * United, West Virginia, an unincorporated community Arts and entertainment Films * ''United'' (2003 film), a Norwegian film * ''United'' (2011 film), a BBC Two f ...

at the base. The ovary consists of three united

carpel Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) '' pistils' ...

s that form a single locule, which produces only one

ovule In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the '' integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the ...

. The ovary is superior with basal or free-central

placentation Placentation refers to the formation, type and structure, or arrangement of the placenta. The function of placentation is to transfer nutrients, respiratory gases, and water from maternal tissue to a growing embryo, and in some instances to remov ...

. The

gynoecium Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils' ...

terminates in 1 to 3 styles, each of which ends in a single stigma.Samuel B. Jones and Arlene E. Luchsinger. 1979. ''Plant systematics''. McGraw-Hill series in organismic biology. New York: McGraw-Hill. Page 254. Walter S. Judd, Christopher S. Campbell, Elizabeth A. Kellogg, Peter F. Stevens, and Michael J. Donoghue. 2008. ''Plant Systematics: A Phylogenetic Approach'', Third Edition. Sinauer Associates: Sunderland, MA, USA. Armen L. Takhtajan (Takhtadzhian). ''Flowering Plants'' second edition (2009), pages 155-156. Springer Science+Business Media. . (see ''External links'' below) Persicaria capitata AF crop

Genera

, Plants of the World Online accepted 56 genera: *'' Acanthoscyphus'' Small *''

Afrobrunnichia Afrobrunnichia is a genus of plants in the family Polygonaceae with two species in West Africa. It is native to Angola, Cameroon, Central African Repu, Congo, Gabon, Ghana, Ivory Coast, Liberia, Nigeria, Sierra Leone and Zaïre. The genus name ...

'' Hutch. & Dalziel *'' Antigonon'' Endl. *'' Aristocapsa'' Reveal & Hardham *'' Atraphaxis'' L. *'' Bactria'' Yurtseva & Mavrodiev *''

Bistorta ''Bistorta'' is a genus of flowering plants in the family Polygonaceae. about 40 species are accepted. It has been supported as a separate clade by molecular phylogenetic analysis. ''Bistorta'' species are native throughout much of the Northern ...

'' (L.) Scop. *'' Brunnichia'' Banks ex Gaertn. *''

Calligonum ''Calligonum'' is a genus of plants in the family Polygonaceae with about 80 species across the Mediterranean Sea region, Asia and North America. Description Plants of the genus ''Calligonum'' are shrubs, diffusely but irregularly branched, wi ...

'' L. *'' Centrostegia'' A.Gray *'' Chorizanthe'' R.Br. ex Benth. *''

'' P.Browne *'' Dedeckera'' Reveal & J.T.Howell *'' Dodecahema'' Reveal & C.B.Hardham *''

Duma A duma (russian: дума) is a Russian assembly with advisory or legislative functions. The term ''boyar duma'' is used to refer to advisory councils in Russia from the 10th to 17th centuries. Starting in the 18th century, city dumas were for ...

'' T.M.Schust. *'' Enneatypus'' Herzog *''

'' Michx. *'' Eskemukerjea'' Malick & Sengupta *''

'' Mill. *''

Fallopia ''Fallopia'' is a genus of about 12 species of flowering plants in the buckwheat family, often included in a wider treatment of the related genus ''Polygonum'' in the past, and previously including '' Reynoutria''. The genus is native to temperat ...

'' Adans. *'' Gilmania'' Coville *'' Goodmania'' Reveal & Ertter *'' Gymnopodium'' Rolfe *'' Harfordia'' Greene & Parry *'' Harpagocarpus'' Hutch. & Dandy *'' Hollisteria'' S.Watson *'' Johanneshowellia'' Reveal *'' Knorringia'' (Czukav.) Tzvelev *'' Koenigia'' L. *'' Lastarriaea'' Remy *'' Leptogonum'' Benth. *'' Magoniella'' Adr.Sanchez *'' Mucronea'' Benth. *''

Muehlenbeckia ''Muehlenbeckia'' or maidenhair is a genus of flowering plants in the family Polygonaceae. It is native to the borders of the Pacific, including South and North America, Papua New Guinea and Australasia. It has been introduced elsewhere, includin ...

'' Meisn. *'' Nemacaulis'' Nutt. *'' Neomillspaughia'' S.F.Blake *'' Oxygonum'' Burch. *''

Oxyria Oxyria is a genus of plants in the family Polygonaceae with three accepted species . It has a circumboreal distribution. Description Species of ''Oxyria'' are perennial herbaceous plants or weakly shrubby. They may have rhizomes. Their stems are ...

'' Hill *'' Oxytheca'' Nutt. *''

Persicaria ''Persicaria'' is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds.Peutalis'' Raf. *'' Podopterus'' Bonpl. *'' Polygonum'' L. *'' Pteropyrum'' Jaub. & Spach *'' Pterostegia'' Fisch. & C.A.Mey. *'' Pteroxygonum'' Dammer & Diels *''

Reynoutria ''Reynoutria'' is a genus of flowering plants in the family Polygonaceae. The genus is native to eastern China, Eastern Asia and the Russian Far East, although species have been introduced to Europe and North America. Members of the genus, includ ...

'' Houtt. *''

'' L. *'' Rumex'' L. *'' Ruprechtia'' C.A.Mey. *'' Salta'' Adr.Sanchez *'' Sidotheca'' Reveal *'' Stenogonum'' Nutt. *'' Symmeria'' Benth. *''

Systenotheca ''Systenotheca'' is a monotypic plant genus in the buckwheat family containing the single species ''Systenotheca vortriedei'', which is known by the common name Vortriede's spineflower. Description This is a small annual plant growing to a maxim ...

'' Reveal & Hardham *''

'' Loefl.

Former genera

*''Aconogonon'' (Meisn.) Rchb. – now included in '' Koenigia'' *''Homalocladium'' (F.Muell.) L.H.Bailey – now included in ''

'' *''Parapteropyrum'' A.J.Li – now included in ''

'' *''Polygonella'' Michx. – now included in '' Polygonum'' *''Rubrivena'' M.Král – now included in '' Koenigia''

Phylogeny

The following phylogenetic tree is based on two papers on the

molecular phylogenetics Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

of Polygonaceae.

Taxonomy

Description

Genera

Former genera

Phylogeny

References

External links