''Oxygonum'' is a

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 ...

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

s in the family

Polygonaceae The Polygonaceae are a Family (biology), family of flowering plants known Common name, informally as the knotweed family or smartweed—buckwheat family in the United States. The Botanical name, name is Basionym, based on the genus ''Polygonum'', ...

with about 30

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

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

Arabian Peninsula The Arabian Peninsula (, , or , , ) or Arabia, is a peninsula in West Asia, situated north-east of Africa on the Arabian plate. At , comparable in size to India, the Arabian Peninsula is the largest peninsula in the world. Geographically, the ...

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 (band), a ...

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

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 o ...

s, more rarely

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 ...

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

s are long narrow

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 ...

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 fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

, 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''. Meaning of the name Francisco In Spanish, people with the name Francisco are sometimes nicknamed "Paco". San Francisco de Asís was known as ''Pater Commu ...

, 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 Kew ...

. ''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 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 the following species: *'' Oxygonum acetosella'' 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 plant, annual or Perennial plant, perennial ...

'' Burch. *'' Oxygonum altissimum'' Germish. *'' Oxygonum annuum'' S.Ortiz & Paiva *'' Oxygonum atriplicifolium'' (Meisn.) Martelli *'' Oxygonum auriculatum'' R.A.Graham *'' Oxygonum buchananii'' (Dammer) J.B.Gillett *'' Oxygonum carnosum'' R.A.Graham *'' Oxygonum delagoense'' Kuntze *'' Oxygonum dregeanum'' Meisn. *'' Oxygonum ellipticum'' R.A.Graham *'' Oxygonum fruticosum'' Dammer ex Milne-Redh. *'' Oxygonum gramineum'' R.A.Graham *'' Oxygonum hastatum'' S.Ortiz *'' Oxygonum hirtum'' Peter *'' Oxygonum leptopus'' Mildbr. *'' Oxygonum limbatum'' R.A.Graham *'' Oxygonum lineare'' De Wild. *'' Oxygonum litorale'' R.A.Graham *'' Oxygonum lobatum'' R.A.Graham *'' Oxygonum maculatum'' R.A.Graham *'' Oxygonum magdalenae'' Dammer ex Peter *'' Oxygonum ovalifolium'' Robyns & E.Petit *'' Oxygonum overlaetii'' Robyns *'' Oxygonum pachybasis'' Milne-Redh. *'' Oxygonum pterocarpum'' Osborne & Vollesen *'' Oxygonum quarrei'' De Wild. *'' Oxygonum robustum'' Germish. *'' Oxygonum sagittatum'' R.A.Graham *'' Oxygonum salicifolium'' Dammer *''

Oxygonum schliebenii ''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 plant, annual or Perennial plant, perennial ...

'' Mildbr. *'' Oxygonum sinuatum'' (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