View source for Atriplex

{{Short description|Genus of flowering plant}}
{{Hatnote|For other plants called saltbush, see [[Saltbush]]}}
{{Automatic taxobox
|image = Atriplex hortensis cleaned Sturm.png
|image_caption = [[Garden orache]] (''[[Atriplex hortensis]]'')<br/>From Sturm & [[Jacob Sturm|Sturm]] (1796): ''Deutschlands Flora in Abbildungen.''
|display_parents = 2
|taxon = Atriplex
|authority = [[Carl Linnaeus|L.]]<ref name="POWO">{{cite web |title=''Atriplex'' L. |url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:30000935-2#synonyms |publisher=Plants of the World Online |access-date=19 June 2022}}</ref>
|type_species = ''[[Atriplex hortensis]]''
|type_species_authority = L.
|synonyms_ref = <ref name="POWO" />
|synonyms = {{collapsible list| 
''Armola'' <small>(Kirschl.) Montandon</small><br/>
''Blackiella'' <small>Aellen</small><br/>
''Cremnophyton'' <small>Brullo & Pavone</small><br/>
''Halimione'' <small>Aellen</small><br/>
''Halimus'' <small>Wallr.</small><br/>
''Haloxanthium'' <small>Ulbr.</small><br/>
''Lophocarya'' <small>Nutt. ex Moq.</small><br/>
''Morrisiella'' <small>Aellen</small><br/>
''Neopreissia'' <small>Ulbr.</small><br/>
''Obione'' <small>Gaertn.</small><br/>
''Pachypharynx'' <small>Aellen</small><br/>
''Phyllocarpa'' <small>Nutt. ex Moq.</small><br/>
''Pterocarya'' <small>Nutt. ex Moq.</small><br/>
''Pterochiton'' <small> Torr. & Frém.</small><br/>
''Schizotheca'' <small>(C.A.Mey.) Lindl.</small><br/>
''Senniella'' <small>Aellen</small><br/>
''Sukhorukovia'' <small>Vasjukov</small><br/>
''Teutliopsis'' <small>(Dumort.) Celak.</small><br/>
''Theleophyton'' <small>Moq.</small><br/>
}}
|subdivision_ranks = Species
|subdivision = See [[List of Atriplex species|List of ''Atriplex'' species]]
}}

'''''Atriplex''''' ({{IPAc-en|ˈ|æ|t|r|ᵻ|p|l|ɛ|k|s}}<ref>''Sunset Western Garden Book,'' 1995:606–607</ref>) is a plant [[genus]] of about 250 species, known by the common names of '''saltbush''' and '''orache''' ({{IPAc-en|ˈ|ɒ|r|ɪ|tʃ|,_|-|ə|tʃ}};<ref>{{Cite book|title=The Chambers Dictionary|publisher=Chambers|year=2003|isbn=0-550-10105-5|edition=9th|chapter=orach}}</ref><ref>{{cite encyclopedia | encyclopedia=[[Oxford English Dictionary]] third edition |title=orache |url=http://www.oed.com/view/Entry/132134 |access-date=7 December 2018| date=June 2004 |publisher=Oxford University Press}}</ref> also spelled '''orach'''). It belongs to the [[subfamily]] [[Chenopodioideae]] of the [[family (biology)|family]] [[Amaranthaceae]] [[sensu|''s.l.'']]. 
The genus is quite variable and widely distributed. It includes many [[desert]] and [[shore|seashore]] plants and [[halophyte]]s, as well as plants of moist environments. 
The generic name originated in [[Latin]] and was applied by [[Pliny the Elder]] to the edible oraches.<ref>{{cite book |url=https://books.google.com/books?id=esMPU5DHEGgC  |first=Umberto |last=Quattrocchi |title=CRC World Dictionary of Plant Names |volume=I: A-C |year=2000 |publisher=CRC Press |isbn=978-0-8493-2675-2 |page=232}}</ref> The name saltbush derives from the fact that the plants retain salt in their leaves; they are able to grow in areas affected by [[soil salination]].

== Description ==
Species of plants in genus ''Atriplex'' are [[Annual plant|annual]] or [[perennial]] herbs, [[subshrub]]s, or shrubs. The plants are often covered with bladderlike hairs, that later collapse and form a silvery, scurfy or mealy surface, rarely with elongate [[trichome]]s. The leaves are arranged alternately along the branches, rarely in opposite pairs, either [[Sessility (botany)|sessile]] or on a [[Petiole (botany)|petiole]], and are sometimes deciduous. The leaf blade is variably shaped and may be entire, tooth or lobed.<ref name="FlNAmerica" /><ref name="FlChina" /><ref name="RBGV" /><ref name="RBGS" /><ref name="FloraBase" />

The flowers are borne in leaf axils or on the ends of branches, in spikes or spike-like [[panicle]]s . The flowers are [[unisexual]], some species [[monoecious]], others [[dioecious]]. Male flowers have 3-5 [[perianth]] lobes and 3-5 [[stamens]]. Female flowers are usually lacking a perianth, but are enclosed by 2 leaf-like [[bracteole]]s, have a short [[Style (botany)|style]] and 2 [[Stigma (botany)|stigmas]].<ref name="FlNAmerica" /><ref name="FlChina" /><ref name="RBGV" /><ref name="RBGS" /><ref name="FloraBase" />

After flowering, the bracteoles sometimes enlarge, thicken or become appendaged, enclosing the fruit but without adhering to it.<ref name="FlNAmerica" /><ref name="FlChina" /><ref name="RBGV" /><ref name="RBGS" /><ref name="FloraBase" />

The [[chromosome]] base number is x = 9, except for ''Atriplex lanfrancoi'', which is x=10.<ref name="Kadereit" />

A few ''Atriplex'' species are [[C3 carbon fixation|C<sub>3</sub>-plants]], but most species are [[C4 carbon fixation|C<sub>4</sub>-plants]], with a characteristic leaf anatomy, known as kranz anatomy.<ref name="Kadereit" />

<gallery mode="packed">
Atriplex elegans.jpg|''[[Atriplex elegans]]''
Atriplex hymenelytra bracts.jpg|''[[Atriplex hymenelytra]]''
Starr 050516-1394 Atriplex lentiformis.jpg|''[[Atriplex lentiformis]]''
Atriplex nummularia.JPG|''[[Atriplex nummularia]]''
Starr 040125-0020 Chenopodium murale.jpg|''[[Atriplex suberecta]]''
Atriplex patula (5129939806).jpg|''[[Atriplex patula]]'', female flower with [[bracteoles]] and [[ovule]]
</gallery>

==Taxonomy==
{{Further|List of Atriplex species|label1=List of ''Atriplex'' species}}

The genus ''Atriplex'' was first formally described in 1753 by [[Carl Linnaeus]] in ''[[Species Plantarum]]''.<ref name="POWO" /><ref name="L.">{{cite book |last1=Linnaeus |first1=Carl |title=Species Plantarum |date=1753 |volume=2 |pages=1052–1053 |url=https://www.biodiversitylibrary.org/item/84236#page/498/mode/1up |access-date=19 June 2022}}</ref><ref name="SpPl" /> The genus name was used by [[Pliny the Elder|Pliny]] for orach, or mountain spinach (''[[Atriplex hortensis|A. hortensis]]'').<ref name="Sharr">{{cite book |last1=Sharr |first1=Francis Aubi |last2=George |first2=Alex |title=Western Australian Plant Names and Their Meanings |date=2019 |publisher=Four Gables Press |location=Kardinya, WA |isbn=9780958034180 |page=61 |edition=3rd}}</ref>

=== Phylogeny ===
The genus evolved in Middle [[Miocene]], the [[C4 carbon fixation|C<sub>4</sub>-photosynthesis]] pathway developed about 14.1–10.9 [[million years ago]] (mya), when the climate became increasingly dry. The genus diversified rapidly and spread over the continents. The C<sub>4</sub> ''Atriplex'' colonized North America probably from Eurasia during the Middle/Late Miocene, about 9.8–8.8 mya, and later spread to South America. Australia was colonized twice by two C<sub>4</sub> lineages, one from Eurasia or America about 9.8–7.8 mya, and one from Central Asia about 6.3–4.8 mya. The last lineage diversified rapidly, and became the ancestor of most Australian ''Atriplex'' species.<ref name="Kadereit" />

=== Systematics ===
The type species ([[lectotype]]) is ''Atriplex hortensis''.<ref name="Tropicos" /> The name is derived from [[Ancient Greek]] ἀτράφαξυς (''atraphaxys''), "orach", itself a [[Pre-Greek substrate]] loanword.

''Atriplex'' is an extremely species-rich genus and comprises about 250<ref name="FlChina" />-300<ref name="Kadereit" /> species, with new species still being discovered. An example includes ''Atriplex yeelirrie'', formally described in 2015.<ref>{{cite journal |last1=Shepherd |first1=Kelly |last2=Thiele |first2=Kevin |last3=Sampson |first3=Jane |last4=Coates |first4=David |last5=Bryne |first5=Margaret |date=2015 |title=A rare, new species of Atriplex (Chenopodiaceae) comprising two genetically distinct but morphologically cryptic populations in arid Western Australia: implications for taxonomy and conservation |url=https://www.publish.csiro.au/sb/SB15029 |journal=Australian Systematic Botany |volume=28 |issue=4 |page=235 |doi=10.1071/SB15029 |access-date=8 September 2021 |s2cid=85903596}}</ref>

Traditional [[taxonomy (biology)|taxonomy]] of [[Atripliceae]] based on morphological features has been controversial.<ref name="Cladistic">{{Cite journal |last1=Flores |first1=Hilda |last2=Davis |first2=Jerrold I. |year=2001 |title=A Cladistic Analysis of Atripliceae (Chenopodiaceae) Based on Morphological Data |url=https://www.researchgate.net/publication/274809339 |journal=Journal of the Torrey Botanical Society |volume=128 |issue=3 |page=297 |doi=10.2307/3088719 |jstor=3088719}}</ref> Molecular studies have found that many genera are not true [[clade]]s. One such study found that Atripliceae could be divided into two main clades, ''Archiatriplex'', with a few, scattered species, and the larger ''Atriplex'' clade, which is highly diverse and found around the world.<ref name="Cladistic" /> After [[phylogenetic]] research, Kadereit et al. (2010) excluded ''[[Halimione]]'' as a distinct sister genus. The remaining ''Atriplex'' species were grouped into several clades.<ref name="Kadereit" />

The following is a cladogram with estimated divergence times for the tribe Atripliceae. To infer the phylogeny, an ITS matrix composed of spacer ITS-1, the 5.8S subunit, and spacer ITS-2 were amplified and sequenced for each specimen. Not all species in the genus ''Atriplex'' are presented in the cladogram (based on page 7 of <ref name="unexpected insights">{{cite journal |last1=Brignone |first1=Nicolás F. |last2=Pozner |first2=Raúl E. |last3=Denham |first3=Silvia S. |date=October 2019 |title=Origin and evolution of Atriplex (Amaranthaceae s.l.) in the Americas: Unexpected insights from South American species |journal=Taxon |volume=68 |issue=5 |page=1027 |doi=10.1002/tax.12133 |s2cid=214371753}}</ref>). This work suggested that the Americas were colonised by C4 ''Atriplex'' from Eurasia or Australia. Furthermore, that in the Americas ''Atriplex'' first appeared in South America, where two lineages underwent ''in situ'' diversification and evolved sympatrically. North America was then colonised by ''Atriplex'' from South America, then one lineage later moved back to South America.<ref name="unexpected insights" />
{{collapse top|title=Cladogram of estimated divergences within the genus ''Atriplex''}}
[[File:World distribution of Atriplex.svg|thumb|upright=2|right|
Background colour in cladogram represents the region where a species is endemic.
 {{legend|#fffde8|South America}}
 {{legend|#ffebeb|North America}}
 {{legend|#e4ffe6|Australia}}
 {{legend|#e1f8ff|Eurasia}}]]
[[File:Unexpected insights hypothesis.svg|thumb|upright=2|right|Brignone et al. (2019) hypothesis for the evolution and movement of ''Atriplex'' species globally.<ref name="unexpected insights" />]]
{{clade| style=font-size:100%; line-height:100%
|label1=[[Atripliceae]]
|1={{clade
   |label1=''Atriplex''
   |1={{clade
      |1={{clade 
         |1={{clade
            |1={{clade
               |1={{clade
                  |1={{clade
                     |1={{clade
                        |1={{clade
                           |1={{clade
                              |1={{clade
                                 |1={{clade
                                    |1={{clade
                                       |1={{clade
                                          |style1=background-color:#fffde8
                                          |1={{clade hidden |id=1 |mode=left
                                             |expand-text=(15 more species, click to view) 
                                             |1={{clade sequential
                                                |1=''[[Atriplex pentandra]]''
                                                |2=''[[Atriplex hystrix]]''
                                                |3=''[[Atriplex clivicola]]''
                                                |4=''[[Atriplex taltalensis]]''
                                                |5=''[[Atriplex vallenarensis]]''
                                                |6=''[[Atriplex peruviana]]''
                                                }}
                                             |2={{clade
                                                |1={{clade sequential
                                                   |1=''[[Atriplex leuca]]''
                                                   |2=''[[Atriplex philippii]]''
                                                   |3=''[[Atriplex myriophylla]]''
                                                   |4=''[[Atriplex chapinii]]''
                                                   |5=''[[Atriplex chizae]]''
                                                   |6=''[[Atriplex frigida]]''
                                                   |7=''[[Atriplex ameghinoi]]''
                                                   }}
                                                |2={{clade
                                                   |1=''[[Atriplex monevidensis]]''
                                                   |2=''[[Atriplex pamparum]]''
                                                   }}
                                                }}
                                             }}
                                          |style2=background-color:#ffebeb
                                          |2=''[[Atriplex serenana]]''
                                          }}
                                       |style2=background-color:#ffebeb
                                       |2={{clade
                                          |1=''[[Atriplex leucophylla]]''
                                          |2=''[[Atriplex watsonii]]''
                                          }}
                                       }}
                                    |style2=background-color:#ffebeb
                                    |2={{clade
                                       |1={{clade
                                          |1=''[[Atriplex acanthocarpa]]''
                                          |2=''[[Atriplex polycarpa]]''
                                          }}
                                       |2={{clade
                                          |1={{clade
                                             |1=''[[Atriplex canescens]]''
                                             |2=''[[Atriplex phyllostegia]]''
                                             }}
                                          |2={{clade
                                             |1=''[[Atriplex obovata]]''
                                             |2=''[[Atriplex powellii]]''
                                             }}
                                          }}
                                       }}
                                    }}
                                 |style2=background-color:#ffebeb
                                 |2=''[[Atriplex parishii]]''
                                 }}
                              |style2=background-color:#ffebeb
                              |2={{clade
                                 |1=''[[Atriplex hymenelytra]]''
                                 |2=''[[Atriplex parryi]]''
                                 }}
                              }}
                           |style2=background-color:#ffebeb
                           |2=''[[Atriplex lentiformis]]''
                           }}
                        |style2=background-color:#fffde8
                        |2={{clade
                           |1={SUBCLADE_A}
                           |2={{clade
                              |1=''[[Atriplex rotundifolia]]''
                              |2=''[[Atriplex imbricata]]''
                              }}
                           }}
                        }}
                     |targetA ={SUBCLADE_A}
                     |subcladeA={{clade
                                |1={{clade
                                   |1={{clade
                                      |1={{clade
                                         |1={{clade
                                            |1={{clade sequential
                                               |1=''[[Atriplex undulata]]''
                                               |2=''[[Atriplex patagonica]]''
                                               |3=''[[Atriplex lithophila]]''
                                               |4=''[[Atriplex atacamensis]]''
                                               }}
                                            |2={{clade
                                               |1={{clade
                                                  |1=''[[Atriplex braunii]]''
                                                  |2=''[[Atriplex oreophila]]''
                                                  }}
                                               |2={{clade
                                                  |1={{clade sequential
                                                     |1=''[[Atriplex retusa]]''
                                                     |2=''[[Atriplex rusbyi]]''
                                                     |3=''[[Atriplex quixadensis]]''
                                                     }}
                                                  |2={{clade
                                                     |1=''[[Atriplex sagittifolia]]''
                                                     |2=''[[Atriplex vulgatissima]]''
                                                     }}
                                                  }}
                                               }}
                                            }} 
                                         |2={{clade
                                            |1=''[[Atriplex cordubensis]]''
                                            |2=''[[Atriplex lampa]]''
                                            }}
                                         }}
                                      |2=''[[Atriplex crenatifolia]]''
                                      }}
                                   |2={{clade
                                      |1={{clade sequential
                                         |1=''[[Atriplex coquimbana]]''
                                         |2=''[[Atriplex costellata]]''
                                         |3=''[[Atriplex repanda]]''
                                         }}
                                      |2={{clade
                                         |1=''[[Atriplex sorianoi]]''
                                         |2=''[[Atriplex spegazzinii]]''
                                         }}
                                      }}
                                   }}
                                |2={{clade
                                   |1=''[[Atriplex boecheri]]''
                                   |2=''[[Atriplex nitrophiloides]]''
                                   }}
                                }}
                             }}
                          |2={{clade
                             |style1=background-color:#fffde8
                             |1={{clade
                                |1=''[[Atriplex argentina]]''
                                |2=''[[Atriplex oesteophora]]''
                                }}
                             |style2=background-color:#fffde8
                             |2=''[[Atriplex asplundii]]''
                             }}
                          }}
                       |style2=background-color:#e4ffe6 
                       |2={{clade
                          |1={{clade
                             |1=''[[Atriplex cinerea]]''
                             |2=''[[Atriplex rhagodioides]]''
                             }}
                          |2={{clade
                             |1=''[[Atriplex isatidea]]''
                             |2=''[[Atriplex nummularia]]''
                             }}
                          }}
                       }}
                    |style2=background-color:#e1f8ff
                    |2={{clade
                       |1=''[[Atriplex halimus]]''
                       |2=''[[Atriplex leucoclada]]''
                       }}
                    }} 
                 |2={{clade
                    |1={{clade
                       |1={{clade
                          |1={{clade
                             |style1=background-color:#e4ffe6 
                             |1={{clade
                                |1={{clade
                                   |1={{clade sequential
                                      |1=''[[Atriplex billardierei]]''
                                      |2=''[[Atriplex holocarpa]]''
                                      |3=''[[Atriplex vesicaria]]''
                                      }}
                                   |2=''[[Atriplex spongiosa]]''
                                   }}
                                |2={{clade sequential
                                   |1=''[[Atriplex semibaccata]]''
                                   |2=''[[Atriplex muelleri]]''
                                   |3=''[[Atriplex suberecta]]''
                                   |4=''[[Atriplex eardleyae]]''
                                   }}
                                }}
                             |style2=background-color:#e1f8ff 
                             |2={{clade
                                |1={{clade
                                   |1=''[[Atriplex centralasiatica]]''
                                   |2=''[[Atriplex siberirica]]''
                                   }}
                                |2={{clade
                                   |1=''[[Atriplex rosea]]''
                                   |2=''[[Atriplex sphaeromorpha]]''
                                   }}
                                }}
                             }}
                          |style2=background-color:#e1f8ff 
                          |2={{clade
                             |1={{clade
                                |1=''[[Atriplex dimorphostegia]]''
                                |2=''[[Atriplex laciniata]]''
                                }}
                             |2=''[[Atriplex tatarica]]''
                             }}
                          }}
                       |style2=background-color:#e1f8ff 
                       |2=''[[Atriplex moneta]]''
                       }}
                    |label2=C3 ''Atriplex'' clade
                    |2={{clade
                       |1={{clade
                          |label1= sect. Teutliopsis
                          |1={{clade
                             |1={{clade
                                |1={{clade
                                   |1={{clade
                                      |style1=background-color:#e4ffe6
                                      |1=''[[Atriplex australasica]]''
                                      |style2=background-color:#e1f8ff
                                      |2=''[[Atriplex glabriuscula]]'' 
                                      }}
                                   |style2=background-color:#e1f8ff
                                   |2=''[[Atriplex micrantha]]''
                                   }}
                                |style2=background-color:#e1f8ff 
                                |2={{clade
                                   |1=''[[Atriplex latifolia]]''
                                   |2=''[[Atriplex oblongifolia]]''
                                   }}
                                }}
                             |style2=background-color:#e1f8ff
                             |2={{clade
                                |1={{clade
                                   |1=''[[Atriplex calotheca]]''
                                   |2=''[[Atriplex prostrata]]''
                                   }}
                                |2={{clade
                                   |1=''[[Atriplex patula]]''
                                   |style2=background-color:#fffde8
                                   |2=''[[Atriplex chilensis]]''
                                   }}
                                }} 
                             }}
                          |label2=sect. ''Atriplex''
                          |style2=background-color:#e1f8ff
                          |2={{clade
                             |1=''[[Atriplex aucherii]]''
                             |2=''[[Atriplex hortensis]]''
                             }}
                          }}
                       |style2=background-color:#e1f8ff
                       |2=''[[Atriplex crassifolia]]''
                       }}
                    }}
                 }}
              |style2=background-color:#e1f8ff
              |2={{clade
                 |1=''[[Atriplex lanfrancoi]]''
                 |2=''[[Atriplex cana]]''
                 }}
              }}
           |style2=background-color:#e1f8ff
           |label2=''[[Halimione]]''
           |2={{clade
              |1=''[[Halimione portulacoides]]''
              |2=''[[Halimione verrucifera]]''
              }}
           }}
        |label2=Archiatriplex clade
        |style2=background-color:#ffebeb
        |2={{clade
           |1=''[[Extriplex californica]]''
           |2=(13 other taxa)
           }}
        }}
{{collapse bottom}}
{{collapse top|title=Clades of ''Atriplex''|left=yes}}
*''Atriplex lanfrancoi/cana''-Clade: 
**''Atriplex lanfrancoi'' (Brullo & Pavone) G. Kadereit et Sukhor. (Syn.: ''Cremnophyton lanfrancoi'' Brullo & Pavone): endemic to [[Malta]] and [[Gozo]].
**''Atriplex cana'' C.A. Mey.: from Eastern European Russia to western China.
*''Atriplex'' section ''Atriplex'': annual C<sub>3</sub>-plants. 
**''Atriplex aucheri'' Moq.: in Eastern Europe and West Asia.
** ''[[Atriplex hortensis]]'' L. &ndash; [[Garden orache]], [[Atriplex hortensis|red orach]], [[mountain spinach]], [[French spinach]]: in Asia, cultivated or naturalized in Europe.
** ''Atriplex oblongifolia'' Waldst. & Kit. &ndash; Oblong-leaved orache: in Eurasia.
** ''Atriplex sagittata'' Borkh. (Syn.: ''Atriplex nitens'' Schkuhr): in Eurasia
*''Atriplex'' section ''Teutliopsis'' Dumort.: annual C<sub>3</sub>-plants.
**''Atriplex australasica'' Moq.
** ''Atriplex calotheca'' (Rafn) Fr.: in Northern Europe.
** ''Atriplex davisii'' Aellen: from southern Europe to Egypt.
** ''[[Atriplex glabriuscula]]'' Edmondston &ndash; Northeastern saltbush, Babington's orache, smooth orache, [[Scotland orache]], [[glabrous orache]]: In central and northern Europe.
** ''Atriplex gmelinii'' C.A. Mey. ex Bong. &ndash; Gmelin's saltbush: in Asia and North America.
** ''Atriplex intracontinentalis'' Sukhor.: from Central Europe to Asia.
** ''Atriplex laevis'' C.A. Mey.: in Asia, naturalized in eastern Europe.
** ''Atriplex latifolia'' Wahlenb.: in Eurasia.
** ''[[Atriplex littoralis]]'' L. &ndash; [[Grass-leaved orache]]: in Eurasia and North Africa.
** ''[[Atriplex longipes]]'' Drejer &ndash; Long-stalked orache: in northern Europe.
** ''Atriplex micrantha'' C.A. Mey.: in Asia, naturalized in Europe.
** ''Atriplex nudicaulis'' Boguslaw &ndash; Baltic saltbush: in Eurasia.
** ''[[Atriplex patula]]'' L. &ndash; [[Common orache]], [[spreading orache]]: in Eurasia and North Africa.
** ''Atriplex praecox'' Hülph. &ndash; Early orache: in northern Europe.
** ''Atriplex prostrata'' Moq. &ndash; Spear-leaved orache, thin-leaved orache, triangle orache, fat hen: in Eurasia and North Africa.
* C<sub>4</sub>-''Atriplex''-Clade: containing the majority of species. The traditional classification into sections (sect. ''Obione'', sect. ''Pterochiton'', sect. ''Psammophila'', sect. ''Sclerocalymma'', sect. ''Stylosa'') did not reflect the [[phylogenetical]] relationships and was rejected by Kadereit et al. (2010).<ref name="Kadereit" />
**''[[Atriplex acanthocarpa]]'' (Torr.) S. Watson: in North America.
** ''Atriplex acutibractea'' Anderson: in Australia.
** ''Atriplex altaica'' Sukhor.: in Asia.
** ''Atriplex angulata'' Benth.: in Australia.
** ''Atriplex billardierei'' (Moq.) Hook. f.: in Australia.
** ''[[Atriplex canescens]]'' (Pursh) Nutt. &ndash; [[Chamiso]], [[chamiza]], [[four-winged saltbush]], grey sagebrush: in North America.
** ''Atriplex centralasiatica'' Iljin: in Asia.
** ''[[Atriplex cinerea]]'' Poir. &ndash; [[Grey saltbush]], truganini:<ref>[[Tasmanian languages|Tasmanian]] name, also transcribed ''trucanini, trucaninny, trugannini, trugernanna'', etc. The plant was the namesake for [[Truganini]], among the last of [[Tasmanian Aborigine|her people]].</ref> in Australia
** ''Atriplex codonocarpa'' P.G. Wilson: in Australia.
** ''Atriplex conduplicata'' F. Muell.: in Australia.
** ''[[Atriplex confertifolia]]'' (Torr. & Frém.) S. Watson &ndash; [[Shadscale]] (saltbush): in North America.
** ''Atriplex cordobensis'' Gand. & Stuck.: in South America.
** ''Atriplex deserticola'' Phil.: in South America.
** ''Atriplex dimorphostegia'' Kar. & Kir.: in North Africa.
** ''Atriplex eardleyae'' Aellen: in Australia
** ''Atriplex elachophylla'' F. Muell.: in Australia.
** ''[[Atriplex fissivalvis]]'' F. Muell.: in Australia
** ''Atriplex flabellum'' Bunge ex Boiss.: in Eurasia.
** ''[[Atriplex gardneri]]'' (Moq.) D. Dietr. &ndash; [[Gardner's saltbush]], moundscale: in North America
** ''Atriplex glauca'' L.: in Portugal, Spain and in North Africa.
** ''[[Atriplex halimus]]'' L. &ndash; [[Mediterranean saltbush]], [[sea orache]], [[shrubby orache]]: in south Europe, North Africa and southwest Asia.
** ''Atriplex herzogii'' Standl.: in North America.
** ''[[Atriplex holocarpa]]'' F. Muell.: in Australia.
** ''[[Atriplex hymenelytra]]'' (Torr.) S. Watson &ndash; [[Desert holly]]: in North America.
** ''Atriplex hymenotheca'' Moq.: in Australia.
** ''Atriplex imbricata'' (Moq.) D. Dietr.: in South America.
** ''Atriplex inamoena'' Aellen: in Eurasia.
** ''Atriplex intermedia'' Anderson: in Australia.
** ''Atriplex isatidea'' Moq.: in Australia.
** ''Atriplex laciniata'' L. &ndash; Frosted orache: In western and northern Europe.
** ''Atriplex lampa'' (Moq.) Gillies ex Small: in South America.
** ''Atriplex lehmanniana'' Bunge: in Eurasia.
** ''[[Atriplex lentiformis]]'' (Torr.) S. Watson &ndash; [[Quail bush]]: in North America.
** ''Atriplex leptocarpa'' F. Muell.: in Australia.
** ''Atriplex leucoclada'' Boiss.: in Eurasia.
** ''[[Atriplex leucophylla]]'' (Moq.) D. Dietr.: in North America
** ''[[Atriplex lindleyi]]'' Moq.: in Australia.
** ''Atriplex moneta'' Bunge ex Boiss.: in Eurasia.
** ''Atriplex muelleri'' Benth.: in Australia.
** ''Atriplex nessorhina'' S.W.L. Jacobs: in Australia.
** ''[[Atriplex nummularia]]'' Lindl. &ndash; Old man saltbush, giant saltbush: in Australia.
** ''Atriplex obovata'' Moq.: in North America.
** ''Atriplex pamirica'' Iljin: in Eurasia.
** ''[[Atriplex parishii]]'' S. Watson: in North America
** ''[[Atriplex parryi]]'' S. Watson: in North America
** ''Atriplex parvifolia'' Kunth: in South America.
** ''Atriplex patagonica'' (Moq.) D. Dietr.: in South America.
** ''[[Atriplex phyllostegia]]'' (Torr. ex S. Watson) S. Watson: in North America.
** ''[[Atriplex polycarpa]]'' (Torr.) S. Watson &ndash; [[Allscale]] (saltbush), [[desert saltbush]], [[cattle saltbush]], [[cattle spinach]]: in North America.
** ''[[Atriplex powellii]]'' S. Watson &ndash; Powell's saltbush: in North America.
** ''Atriplex pseudocampanulata'' Aellen: in Australia.
** ''Atriplex quinii'' F. Muell.: in Australia.
** ''Atriplex recurva'' d'Urv.: in Eurasia, endemic to areas around the Aegean.
** ''Atriplex rhagodioides'' F. Muell.: in Australia.
** ''[[Atriplex rosea]]'' L. &ndash; Tumbling orache: in Eurasia and North Africa.
** ''Atriplex rusbyi'' Britton ex Rusby: in South America.
** ''Atriplex schugnanica'' Iljin: in Asia.
** ''[[Atriplex semibaccata]]'' R. Br. &ndash; [[Australian saltbush]], [[berry saltbush]], [[creeping saltbush]]: in Australia.
** ''Atriplex semilunaris'' Aellen: in Australia.
** ''[[Atriplex serenana]]'' A. Nelson ex Abrams: in North America
** ''Atriplex sibirica'' L.; in Asia, naturalized in Europe.
** ''Atriplex sphaeromorpha'' Iljin: in Russia, Ukraine and Caucasus.
** ''Atriplex spinibractea'' Anderson: in Australia.
** ''Atriplex spongiosa'' F. Muell.: in Australia.
** ''[[Atriplex stipitata]]'' Benth.: in Australia.
** ''Atriplex sturtii'' S.W.L. Jacobs: in Australia.
** ''[[Atriplex suberecta]]'' I. Verd. &ndash; Sprawling saltbush, lagoon saltbush: in Australia.
** ''[[Atriplex tatarica]]'' Aellen: in Europe, North Africa and Asia.
** ''Atriplex turbinata'' (Anderson) Aellen: in Australia.
** ''Atriplex undulata'' (Moq.) D. Dietr.: in South America.
** ''Atriplex velutinella'' F. Muell.: in Australia.
** ''[[Atriplex vesicaria]]'' Heward ex Benth. &ndash; [[Bladder saltbush]]: in Australia.
{{collapse bottom}}

== Distribution and habitat ==
The genus ''Atriplex'' is distributed nearly worldwide from [[subtropical]] to [[temperate]] and to [[subarctic]] regions. Most species-rich are [[Australia]], [[North America]], [[South America]] and [[Eurasia]]. Many species are [[halophyte]]s and are adapted to dry environments with salty soils.<ref name="Kadereit" />

== Ecology ==
''Atriplex'' species are used as food plants by the [[larva]]e of some [[Lepidoptera]] species; see the list of Lepidoptera which feed on ''Atriplex''.<ref>{{Cite journal|title=HOSTS - The Hostplants and Caterpillars Database at the Natural History Museum|url=https://www.nhm.ac.uk/our-science/data/hostplants/search/list.dsml?searchPageURL=index.dsml&PGenus=Atriplex&sort=Taxon|access-date=2020-09-28|website=www.nhm.ac.uk| date=2023 | doi=10.5519/havt50xw | last1=Robinson | first1=Gaden S. | last2=Ackery | first2=Phillip R. | last3=Kitching | first3=Ian | last4=Beccaloni | first4=George W. | last5=Hernández | first5=Luis M. }}</ref> They are also sometimes consumed by camels.<ref>{{Cite journal |last=Shawket |first=S. M. |date=1999 |title=Fattening of camel calves on saltbush, Atriplex halimas with different energy sources |url=https://scholar.google.com/scholar_lookup?title=Fattening+of+camel+calves+on+saltbush%2C+Atriplex+halimas+with+different+energy+sources&author=Shawket%2C+S.M.+%28Ministry+of+Agriculture%2C+Cairo+%28Egypt%29.+Desert+Research+Centre%29&publication_year=1999 |journal=Mansoura University, Journal of Agricultural Sciences (Egypt) |language=English |issn=1110-0346}}</ref> For [[spider]]s such as ''[[Phidippus californicus]]'' and other [[arthropod]]s, saltbush plants offer opportunities to hide and hunt in [[habitat]] that is otherwise often quite barren.

It has been proposed that genus ''Atriplex'' was a main food source in the diet of the extinct giant kangaroo ''[[Procoptodon goliah]]''.<ref>{{Cite journal|last1=Prideaux|first1=Gavin J.|last2=Ayliffe|first2=Linda K.|last3=DeSantis|first3=Larisa R. G.|last4=Schubert|first4=Blaine W.|last5=Murray|first5=Peter F.|last6=Gagan|first6=Michael K.|last7=Cerling|first7=Thure E.|date=2009-07-14|title=Extinction implications of a chenopod browse diet for a giant Pleistocene kangaroo|journal=Proceedings of the National Academy of Sciences|language=en|volume=106|issue=28|pages=11646–11650|doi=10.1073/pnas.0900956106|issn=0027-8424|pmid=19556539|pmc=2710660|bibcode=2009PNAS..10611646P|s2cid=19904871|doi-access=free}}</ref> Stable isotopic data suggested that their diet consisted of plants that used the [[C4 photosynthesis|C4 photosynthetic pathway]], and due to their semi-arid distribution, chenopod saltbushes were likely responsible.<ref>{{Cite journal|last1=Kadereit|first1=Gudrun|last2=Mavrodiev|first2=Evgeny V.|last3=Zacharias|first3=Elizabeth H.|last4=Sukhorukov|first4=Alexander P.|date=2010|title=Molecular phylogeny of Atripliceae (Chenopodioideae, Chenopodiaceae): Implications for systematics, biogeography, flower and fruit evolution, and the origin of C4 photosynthesis|url=https://bsapubs.onlinelibrary.wiley.com/doi/abs/10.3732/ajb.1000169|journal=American Journal of Botany|language=en|volume=97|issue=10|pages=1664–1687|doi=10.3732/ajb.1000169|pmid=21616801|issn=1537-2197}}</ref><ref>{{cite journal |last1=Prideaux |first1=G. |title=Systematics and Evolution of the Sthenurine Kangaroos |journal= UC Publications in Geological Sciences |date=2004 |doi=10.1525/california/9780520098459.001.0001 |publisher=University of California Press|isbn=9780520098459 |url=https://escholarship.org/uc/item/9z42c7t1 }}</ref><ref>{{Cite journal|last1=DeSantis|first1=Larisa R. G.|last2=Field|first2=Judith H.|last3=Wroe|first3=Stephen|last4=Dodson|first4=John R.|date=May 2017|title=Dietary responses of Sahul (Pleistocene Australia–New Guinea) megafauna to climate and environmental change|journal=Paleobiology|language=en|volume=43|issue=2|pages=181–195|doi=10.1017/pab.2016.50|bibcode=2017Pbio...43..181D |s2cid=13134989|issn=0094-8373|doi-access=free}}</ref>

== Uses ==
The favored species for human consumption is now usually [[garden orache]] (''A. hortensis''),<ref>{{Cite web|title=Orach facts and health benefits|date=4 February 2020|url=https://www.healthbenefitstimes.com/orach/|access-date=2020-09-28|language=en-US}}</ref><ref>{{Cite web|title=Atriplex hortensis Orach, Garden orache PFAF Plant Database|url=https://pfaf.org/user/Plant.aspx?LatinName=Atriplex+hortensis|access-date=2020-09-28|website=pfaf.org}}</ref><ref>{{Cite web|title=Atriplex hortensis (garden orache)|url=https://www.cabi.org/ISC/datasheet/87637450|access-date=2020-09-28|website=www.cabi.org|language=en}}</ref> but many species are edible and the use of ''Atriplex'' as food is known since at least the late [[Epipaleolithic]] (Mesolithic).

Common orache (''[[Atriplex patula|A. patula]]'') is attested as an [[archaeophyte]] in northern Europe, and the [[Ertebølle culture]] is presumed to have used it as a food.<ref>{{Cite web|url=http://home3.inet.tele.dk/evakoch/veg-uk.htm|archive-url=https://web.archive.org/web/20060717232907/http://home3.inet.tele.dk/evakoch/veg-uk.htm|url-status=dead|archive-date=2006-07-17|title=Prehistoric plant food of Denmark|last=Koch|first=Eva|date=December 1999}}</ref> Its seed has been found among apparent evidence of cereal preparation and cooking at Late Iron Age villages in Britain.<ref>{{citation|title=North West Cambridge Archaeology: University of Cambridge 2013 Excavations, The Traveller's Rest Sub-site|author=Christopher Evans|publisher=Cambridge Archaeological Unit University Of Cambridge|pages=100–113|year=2015|url=http://www-cau.arch.cam.ac.uk/1271%20North%20West%20Cambridge%20Part%208.pdf}}</ref> In the [[Hebrew Bible|biblical]] [[Book of Job]], ''mallûaḥ'' (מַלּ֣וּחַ, probably [[Mediterranean saltbush]], ''A. halimus'', the major culinary saltbush in the region) is mentioned as food eaten by social outcasts ({{bibleverse||Job|30:4|31}}<ref>Mistranslated as "[[Malva|mallow]]s" in the [[King James Bible]] and as ''Nesseln'' ([[Urtica|nettles]]) in the [[Luther Bible]]</ref>). [[Grey saltbush]] (''[[Atriplex cinerea|A. cinerea]]'') has been used as [[bushfood]] in [[Australia]] since prehistoric times.
[[Chamiso]] (''A. canescens'') and [[shadscale]] (''A. confertifolia'') were eaten by [[Indigenous peoples of the Americas|Native Americans]], and spearscale (''A. hastata'') was a food in rural [[Eurasia]].

Studies on ''Atriplex'' species demonstrated their potential use in agriculture. Meat from sheep which have grazed on saltbush has surprisingly high levels of [[vitamin E]], is leaner and more hydrated than regular [[Domestic sheep|lamb]] and has consumer appeal equal to grain-fed lamb.<ref name="Pearce" /> The vitamin E levels could have animal health benefits while extending the shelf-life and maintaining the fresh red colour of saltbush lamb. This effect has been demonstrated for old man saltbush (''[[Atriplex nummularia|A. nummularia]]'') and river saltbush (''[[Atriplex amnicola|A. amnicola]]''). For reasons unknown, sheep seem to prefer the more fibrous, less nutritious river saltbush.<ref name="Norman" /><ref name="Pearce" />

A study on ''A. nummularia'' discovered the species have a nitrogen content of 2.5–3.5%, and could potentially be used as a protein supplement for grazing if palatable.<ref>{{cite journal |author1=Wilson, A.D.|author2= Harrington, G.N. |title=Nutritive value of Australian browse plants |journal=International Livestock Centre for Africa |date=1980 |page=291 |location=Addis Ababa}}</ref> A subsequent study allowed sheep and goats to voluntarily feed on ''[[Atriplex halimus]]'' and aimed to determine if the saltbush was palatable, and if so, did it provide enough nutrients to supplement the diet of these animals.<ref>{{cite journal |author1=Valderrabano, J.|author2=Munoz, F. |author3=Delgado, I. |title=Browsing ability and utilisation by sheep and goats of Atriplex hamilus L. shrubs. |journal=Small Ruminant Research |date=1996 |volume=19 |issue=2 |pages=131–136 |url=https://www.academia.edu/10164599 |access-date=13 April 2020 |location=Zaragoza, Spain|doi=10.1016/0921-4488(95)00754-7 }}</ref> In this study they determined when goats and sheep are given as much ''[[Atriplex halimus|A. halimus]]'' as they like, they do obtain enough nutrients to supplement their diet{{Snd}}unless the animal requirements are higher during pregnancy and milk production.

Saltbushes are also used as an [[ornamental plant]] in [[landscape|landscaping]] and can be used to prevent [[soil erosion]] in coastal areas.<ref>{{Cite web|title=Saltbushes for dryland salinity management in Western Australia|url=https://www.agric.wa.gov.au/soil-salinity/saltbushes-dryland-salinity-management-western-australia|access-date=2020-09-28|website=www.agric.wa.gov.au|language=en}}</ref><ref>{{Cite web|title=Atriplex semibaccata (Australian saltbush)|url=https://www.cabi.org/isc/datasheet/7903|access-date=2020-09-28|website=www.cabi.org|language=en}}</ref> Old man saltbush (''[[Atriplex nummularia]]'') has also been successfully used to rehabilitate old mining sites around [[Lightning Ridge, New South Wales|Lightning Ridge]] (Australia).

== See also ==
*[[Barbara Hulme]], producer of Atriplex hybrids

==References ==
<references>
<ref name="FlNAmerica">Stanley L. Welsh: [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=103110 ''Atriplex'' - online], In: Flora of North America Editorial Committee (ed.): ''Flora of North America North of Mexico'', Volume 4: ''Magnoliophyta: Caryophyllidae, part 1.'', Oxford University Press, New York. 2003, {{ISBN|0-19-517389-9}}.</ref> 
<ref name="FlChina">Gelin Zhu, Sergei L. Mosyakin & Steven E. Clemants: ''Chenopodiaceae'': [http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=103110 ''Atriplex'' - online], In: Wu Zhengyi, Peter H. Raven, Deyuan Hong (ed.): ''Flora of China'', Volume 5: ''Ulmaceae through Basellaceae.'', Science Press und Missouri Botanical Garden Press, Beijing und St. Louis, 2003, {{ISBN|1-930723-27-X}}.</ref> 
<ref name="RBGV">{{cite web |last1=Walsh |first1=Neville G. |title=''Atriples'' |url=https://vicflora.rbg.vic.gov.au/flora/taxon/c41cd3e8-c729-4e74-b251-293ce28c8557 |publisher=Royal Botanic Gardens Victoria |access-date=16 July 2022}}</ref>
<ref name="RBGS">{{cite web |last1=Jacobs |first1=Surrey W.L. |title=''Atriplex'' |url=https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&showsyn=&dist=&constat=&lvl=gn&name=Atriplex |publisher=Royal Botanic Garden Sydney |access-date=16 July 2022}}</ref>
<ref name=FloraBase>{{FloraBase|name=''Atriplex''|id=21347}}</ref>
<ref name="Kadereit">Gudrun Kadereit, Evgeny V. Mavrodiev, Elizabeth H. Zacharias & Alexander P. Sukhorukov: Molecular phylogeny of Atripliceae (Chenopodioideae, Chenopodiaceae): Implications for systematics, biogeography, flower and fruit evolution, and the origin of C4 Photosynthesis. - ''American Journal of Botany'' 97(10): 1664-1687, 2010.</ref> 
<ref name="Norman">{{aut|Norman, Hayley C.; Freind, Colby; Masters, David G.; Rintoul, Allan J.; Dynes, Robyn A. & Williams, Ian H.}} (2004): Variation within and between two saltbush species in plant composition and subsequent selection by sheep. ''[[Australian Journal of Agricultural Research|Aust. J. Agr. Res.]]'' '''55'''(9): 999–1007. {{doi|10.1071/AR04031}} (HTML abstract)</ref>
<ref name="Pearce">{{aut|Pearce, Kelly & Jacob, Robin}} (2004): Saltbush lifts sheep meat vitamin content. ''Farming Ahead'' '''153'''(October): 63. [http://www.csiro.au/proprietaryDocuments/Saltbush_vitamin.pdf PDF fulltext] {{webarchive |url=https://web.archive.org/web/20050723234637/http://www.csiro.au/proprietaryDocuments/Saltbush_vitamin.pdf |date=July 23, 2005 }}</ref>
<ref name="SpPl">{{citation |chapter-url=https://www.biodiversitylibrary.org/page/359073 |volume=2 |chapter=''Atriplex'' |title= ''[[Species Plantarum]]'' |author=Carl Linnaeus |publisher=Lars Salvius/Biodiversity Heritage Library |date=1753|access-date=19 May 2015 |pages=1052–1054}}</ref> 
<ref name="Tropicos">[http://www.tropicos.org/Name/40022497 ''Atriplex''] at Tropicos, accessed 2013-07-11</ref>
</references>

* {{aut|Davidson, Alan}} (1999): Orach. ''In: Oxford Companion to Food'': 556. <small>{{ISBN|0-19-211579-0}}</small>
* {{Cite book |last1=Everitt |first1=J.H. |last2=Lonard |first2=R.L. |last3=Little |first3=C.R. |title=Weeds in South Texas and Northern Mexico |publisher=Texas Tech University Press |location=Lubbock |year=2007}} {{ISBN|0-89672-614-2}}

{{Taxonbar|from=Q157801}}
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[[Category:Atriplex| ]]
[[Category:Halophytes]]
[[Category:Drought-tolerant plants]]
[[Category:Garden plants]]
[[Category:Amaranthaceae genera]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Pseudocereals]]
[[Category:Chenopodioideae]]