Atraphaxis 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 ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

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 40

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), ...

Description

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

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 (biology ...

s are membranous and usually two-veined, more-or-less joined at the base. 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 ...

is made up of several bundles ( fascicles) of one to three flowers. The flowers have persistent

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, either arranged in a narrow tube with unequal lobes or bell-shaped with equal segments. The fruits are wingless

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 ...

Taxonomy

The genus ''Atraphaxis'' was erected by

Carl Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

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 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 ...

studies have shown that ''Atraphaxis'' forms a distinct clade. The genus is placed in the tribe Polygoneae 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' ...

. Within the tribe, it is most closely related to the genera ''

Duma A duma () 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 formed across Russia ...

'' and ''

Polygonum ''Polygonum'' is a genus of about 130 species of flowering plants in the buckwheat and knotweed family Polygonaceae. Common names include knotweed and knotgrass (though the common names may refer more broadly to plants from Polygonaceae). In the ...

'', forming the so-called "DAP clade".

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 41 species: *'' Atraphaxis angustifolia'' Jaub. & Spach *'' Atraphaxis ariana'' (Grigorj.) T.M.Schust. & Reveal *'' Atraphaxis arida'' (Boiss. & Hausskn.) S.Tavakkoli & Kaz.Osaloo *'' Atraphaxis atraphaxiformis'' (Botsch.) T.M.Schust. & Reveal *'' Atraphaxis aucheri'' Jaub. & Spach *'' Atraphaxis avenia'' Botsch. *'' Atraphaxis badghysi'' Kult. *'' Atraphaxis billardierei'' Jaub. & Spach *'' Atraphaxis binaludensis'' S.Tavakkoli, Mozaff. & Kaz.Osaloo *'' Atraphaxis botuliformis'' (Mozaff.) S.Tavakkoli & Mozaff. *'' Atraphaxis bracteata'' Losinsk. *'' Atraphaxis canescens'' Bunge *'' Atraphaxis caucasica'' (Hoffm.) Pavlov *'' Atraphaxis compacta'' Ledeb. *'' Atraphaxis daghestanica'' (Lovelius) Lovelius *'' Atraphaxis decipiens'' Jaub. & Spach *'' Atraphaxis dumosa'' (Boiss.) S.Tavakkoli & Kaz.Osaloo *'' Atraphaxis frutescens'' (L.) K.Koch *'' Atraphaxis grandiflora'' Willd. *'' Atraphaxis intricata'' Mozaff. *'' Atraphaxis irtyschensis'' Chang Y.Yang & Y.L.Han *'' Atraphaxis kamelinii'' Yurtseva *'' Atraphaxis karataviensis'' Pavlov & Lipsch. *'' Atraphaxis kermanica'' S.Tavakkoli & Kaz.Osaloo *'' Atraphaxis khajeh-jamali'' (Khosravi & Poormahdi) S.Tavakkoli & Kaz.Osaloo *'' Atraphaxis kopetdagensis'' Kovalevsk. *'' Atraphaxis laetevirens'' (Ledeb.) Jaub. & Spach *'' Atraphaxis macrocarpa'' Rech.f. & Schiman-Czeika *'' Atraphaxis manshurica'' Kitag. *'' Atraphaxis muschketowii'' Krasn. *'' Atraphaxis popovii'' (Borodina) Yurtseva *'' Atraphaxis pungens'' (M.Bieb.) Jaub. & Spach *'' Atraphaxis pyrifolia'' Bunge *'' Atraphaxis radkanensis'' S.Tavakkoli, Kaz.Osaloo & Mozaff. *'' Atraphaxis rodinii'' Botsch. *'' Atraphaxis salicornioides'' (Jaub. & Spach) S.Tavakkoli & Kaz.Osaloo *'' Atraphaxis seravschanica'' Pavlov *'' Atraphaxis spinosa'' L. *'' Atraphaxis suaedifolia'' Jaub. & Spach *'' Atraphaxis teretifolia'' (Popov) Kom. *'' Atraphaxis toktogulica'' (Lazkov) T.M.Schust. & Reveal

References

{{Taxonbar, from=Q889292 Polygonoideae Polygonaceae genera