Atraphaxis is a genus of flowering plants in the family Polygonaceae with about 40 species.

Atraphaxis
Atraphaxis pyrifolia
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Order: Caryophyllales
Family: Polygonaceae
Subfamily: Polygonoideae
Genus: Atraphaxis
L.[1]
Species

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Synonyms[1]
  • Persicaria Neck.
  • Tragopyrum M.Bieb.

Description

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Species of Atraphaxis are much branched woody plants, forming shrubs or shrubby tufts. The current year's branchlets are herbaceous and bear the leaves and flowers. The leaves are simple and alternate, with very short stalks (almost sessile). The ochreas are membranous and usually two-veined, more-or-less joined at the base. The inflorescence is made up of several bundles (fascicles) of one to three flowers. The flowers have persistent tepals, either arranged in a narrow tube with unequal lobes or bell-shaped with equal segments. The fruits are wingless achenes.[2]

Taxonomy

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The genus Atraphaxis was erected by Carl Linnaeus in 1753. As with many other genera in the family Polygonaceae, the boundaries between the genera have been unclear, and some or all species placed in other genera. Molecular phylogenetic studies have shown that Atraphaxis forms a distinct clade.[2][3] The genus is placed in the tribe Polygoneae of the subfamily Polygonoideae. Within the tribe, it is most closely related to the genera Duma and Polygonum, forming the so-called "DAP clade".[3]

Polygoneae

Knorringia

Polygonum ciliinode (syn. Fallopia ciliinodis)

DAP clade
RMF clade

Species

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As of March 2019, Plants of the World Online accepted 41 species:[1]

References

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  1. ^ a b c "Atraphaxis L.", Plants of the World Online, Royal Botanic Gardens, Kew, retrieved 2019-03-04
  2. ^ a b Tavakkoli, S.; Osaloo, S.K.; Mozaffarian, V. & Maassoumi, A.A. (2015), "Molecular phylogeny of Atraphaxis and the woody Polygonum species (Polygonaceae): Taxonomic implications based on molecular and morphological evidence", Plant Systematics and Evolution, 301 (4): 1157–1170, Bibcode:2015PSyEv.301.1157T, doi:10.1007/s00606-014-1140-7, S2CID 254058909
  3. ^ a b 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