''Oxygonum'' is a

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 ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

s in the family

Polygonaceae The Polygonaceae are a family of flowering plants known informally as the knotweed family or smartweed—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 ...

with about 30

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 ...

. It is native to eastern parts of Africa and to the

Arabian Peninsula The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Plate ...

Description

Species of ''Oxygonum'' are

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 ...

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 wide ...

herbaceous plant Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of t ...

s, more rarely

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 or shrubby. Their leaves are variable between and within 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 ...

s are long narrow

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 ...

s with bundles (fascicles) of flowers, usually one to five, but sometimes up to 15. The flowers are polygamous (i.e. there are male, female and bisexual flowers on the same plant). There are usually five

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

s, arranged spirally, fused at the base to form a tube, longer in female flowers than in male ones. The eight stamens are joined at the base, with patches of nectar-bearing tissue at the base of the inner whorl. The fruit is in the form of an

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not ope ...

, usually three-angled, often with rows of spinelike structures.

Taxonomy

The genus ''Oxygonum'' was first published in 1819 by

Francisco Campderá Francisco is the Spanish and Portuguese form of the masculine given name ''Franciscus''. Nicknames In Spanish, people with the name Francisco are sometimes nicknamed "Paco". San Francisco de Asís was known as ''Pater Comunitatis'' (father of ...

, who attributed the name to

William John Burchell __NOTOC__ William John Burchell (23 July 1781 – 23 March 1863) was an English explorer, naturalist, traveller, artist, and author. His thousands of plant specimens, as well as field journals from his South African expedition, are held by Ke ...

. ''Oxygonum'' is placed in the tribe Oxygoneae of the subfamily

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'' ...

; it is the only genus in the tribe. A 2015 molecular phylogenetic study suggested that it was the sister of all the remaining tribes.

Species

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 the following species: *''

Oxygonum acetosella ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Welw. *''

Oxygonum alatum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Burch. *'' Oxygonum altissimum'' Germish. *''

Oxygonum annuum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' S.Ortiz & Paiva *''

Oxygonum atriplicifolium ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' (Meisn.) Martelli *''

Oxygonum auriculatum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' R.A.Graham *''

Oxygonum buchananii ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' (Dammer) J.B.Gillett *''

Oxygonum carnosum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' R.A.Graham *''

Oxygonum delagoense ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Kuntze *''

Oxygonum dregeanum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Meisn. *''

Oxygonum ellipticum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' R.A.Graham *''

Oxygonum fruticosum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Dammer ex Milne-Redh. *''

Oxygonum gramineum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' R.A.Graham *'' Oxygonum hastatum'' S.Ortiz *'' Oxygonum hirtum'' Peter *''

Oxygonum leptopus ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Mildbr. *'' Oxygonum limbatum'' R.A.Graham *''

Oxygonum lineare ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' De Wild. *'' Oxygonum litorale'' R.A.Graham *''

Oxygonum lobatum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' R.A.Graham *'' Oxygonum maculatum'' R.A.Graham *''

Oxygonum magdalenae ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Dammer ex Peter *''

Oxygonum ovalifolium ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Robyns & E.Petit *'' Oxygonum overlaetii'' Robyns *''

Oxygonum pachybasis ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' Milne-Redh. *'' Oxygonum pterocarpum'' Osborne & Vollesen *'' Oxygonum quarrei'' De Wild. *'' Oxygonum robustum'' Germish. *''

Oxygonum sagittatum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' R.A.Graham *'' Oxygonum salicifolium'' Dammer *'' Oxygonum schliebenii'' Mildbr. *''

Oxygonum sinuatum ''Oxygonum'' is a genus of plants in the family Polygonaceae with about 30 species. It is native to eastern parts of Africa and to the Arabian Peninsula. Description Species of ''Oxygonum'' are annual or perennial herbaceous plants, more rarely ...

'' (Hochst. & Steud. ex Meisn.) Dammer *'' Oxygonum stuhlmannii'' Dammer *'' Oxygonum subfastigiatum'' R.A.Graham *'' Oxygonum tenerum'' Milne-Redh. *'' Oxygonum thulinianum'' S.Ortiz *'' Oxygonum wittei'' Staner

References

{{Taxonbar, from=Q7115979 Polygonaceae genera Polygonoideae