Oxygonum

Life-forms

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Ordo: Caryophyllales

Familia: Polygonaceae
Subfamilia: Polygonoideae
Tribus: Oxygoneae
Genus: Oxygonum
Species: O. acetosella – O. alatum – O. altissimum – O. annuum – O. atriplicifolium – O. auriculatum – O. buchananii – O. carnosum – O. delagoense – O. dentatum – O. dregeanum – O. ellipticum – O. fruticosum – O. gramineum – O. hastatum – O. hirtum – O. leptopus – O. limbatum – O. lineare – O. litorale – O. lobatum – O. magdalenae – O. ovalifolium – O. pachybasis – O. quarrei – O. robustum – O. sagittatum – O. salicifolium – O. schliebenii – O. sinuatum – O. stuhlmannii – O. subfastigiatum – O. tenerum – O. thulinianum – O. tristachyum – O. vanderystii
Name

Oxygonum Burch. ex Campd., Monogr. Rumex 18 (1819).

Type species: Oxygonum alatum Burch., Monogr. Rumex 18 (1819).

Synonyms

Heterotypic
Ceratogonon Meisn., Pl. Asiat. Rar. 3: 63 (1832).

References
Primary references

Campderá, F. 1819. Monographie des Rumex p. 18.

Additional references

Schuster, T.M., Reveal, J.L., Bayly, M.J. & Kron, K.A. 2015. An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia. Taxon 64(6): 1188–1208. DOI: 10.12705/646.5 JSTOR ResearchGate Reference page.

Links

African Plants Database (version 3.4.0). Oxygonum. Conservatoire et Jardin botaniques de la Ville de Genève and South African National Biodiversity Institute, Pretoria. Accessed: 2017 Mar. 12.
International Plant Names Index. 2017. Oxygonum. Published online. Accessed: Mar. 12 2017.
The Plant List 2013. Oxygonum in The Plant List Version 1.1. Published on the internet. Accessed: 2017 Mar. 12.
Tropicos.org 2017. Oxygonum. Missouri Botanical Garden. Published on the internet. Accessed: 2017 Mar. 12.
USDA, ARS, Germplasm Resources Information Network. Oxygonum in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 09-Oct-10.

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.[1]

Description

Species of Oxygonum are annual or perennial herbaceous plants, more rarely shrubs or shrubby. Their leaves are variable between and within species. The inflorescences are long narrow racemes 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 tepals, 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, usually three-angled, often with rows of spinelike structures.[2]
Taxonomy

The genus Oxygonum was first published in 1819 by Francisco Campderá, who attributed the name to William John Burchell.[1][3] Oxygonum is placed in the tribe Oxygoneae of the subfamily Polygonoideae; it is the only genus in the tribe. A 2015 molecular phylogenetic study suggested that it was the sister of all the remaining tribes.[2]

Polygonoideae	Oxygoneae (Oxygonum)       Persicarieae       Fagopyreae       Pteroxygoneae       Calligoneae       Rumiceae     Polygoneae

 
 
Species

As of March 2019, Plants of the World Online accepted the following species:[1]

Oxygonum acetosella Welw.
Oxygonum alatum 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 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

"Oxygonum Burch.", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2019-03-08
Schuster, Tanja M.; Reveal, James L.; Bayly, Michael J. & Kron, Kathleen A. (2015), "An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of Oxygonum, Pteroxygonum, and Rumex, and a new circumscription of Koenigia", Taxon, 64 (6): 1188–1208, doi:10.12705/646.5
Campderá, Francisco (1819), "Genarum Polygonaearum Clavis Dichotomica", Monographie des Rumex, Paris: Treuttel & Würtz, retrieved 2019-03-08