Editing Amaranth (section)

== Taxonomy ==
''Amaranthus'' shows a wide variety of morphological diversity among and even within certain species. ''Amaranthus'' is part of the Amaranthaceae that is part of the larger grouping of the Carophyllales.<ref name=schmid/> Although the family ([[Amaranthaceae]]) is distinctive, the [[genus]] has few distinguishing characters among the 75 species present across six continents.<ref name=stetter1/> This complicates [[taxonomy (biology)|taxonomy]] and ''Amaranthus'' has generally been considered among systematists as a "difficult" genus and to hybridize often.<ref name="Costea">{{cite journal |last1=Costea |first1=Mihai |last2=DeMason |first2=Darleen A. |s2cid=84211686 |title=Stem Morphology and Anatomy in ''Amaranthus'' L. (Amaranthaceae), Taxonomic Significance |journal=Journal of the Torrey Botanical Society |volume=128 |issue=3 |year=2001 |issn=1095-5674 |doi=10.2307/3088717 |page=254 |jstor=3088717}}</ref>

In 1955, Sauer classified the genus into two subgenera, differentiating only between monoecious and dioecious species: ''Acnida'' (L.) Aellen ex K.R. Robertson and ''Amaranthus''.<ref name="Costea" /> Although this classification was widely accepted, further infrageneric classification was (and still is) needed to differentiate this widely diverse group. Mosyakin and Robertson 1996 later divided into three subgenera: Acnida, Amaranthus, and Albersia.<ref>{{Cite journal |last1=Mosyakin |first1=Sergei L. |last2=Clemants |first2=Steven E. |date=1996 |title=New Infrageneric Taxa and Combinations in Chenopodium L. (Chenopodiaceae) |journal=Novon |volume=6 |issue=4 |pages=398 |doi=10.2307/3392049 |issn=1055-3177 |jstor=3392049 |url=https://www.biodiversitylibrary.org/part/28372}}</ref> The support for the addition of the subdivision Albersia because of its [[Dehiscence (botany)|indehiscent]] fruits coupled with three elliptic to linear [[tepal]]s to be exclusive characters to members of this subgenus. The classification of these groups are further supported with a combination of  floral characters, reproductive strategies, geographic distribution, and molecular evidence.<ref name="stetter1">{{Cite journal|journal=Molecular Phylogenetics and Evolution|volume=109|pages=80–92|date=April 2017|title=Analysis of phylogenetic relationships and genome size evolution of the ''Amaranthus'' genus using GBS indicates the ancestors of an ancient crop |last1=Stetter |first1=Markus G. |last2=Schmid |first2=Karl J|doi=10.1016/j.ympev.2016.12.029|pmid=28057554 |doi-access=free|bibcode=2017MolPE.109...80S }}</ref><ref name="wasel">{{Cite journal |last1=Waselkov |first1=Katherine E. |last2=Boleda |first2=Alexis S. |last3=Olsen |first3=Kenneth M. |date=2018-06-21 |title=A Phylogeny of the Genus ''Amaranthus'' (Amaranthaceae) Based on Several Low-Copy Nuclear Loci and Chloroplast Regions |journal=Systematic Botany |volume=43 |issue=2 |pages=439–458 |doi=10.1600/036364418x697193 |s2cid=49568120 |issn=0363-6445}}</ref><ref>{{Cite journal |last1=Clouse |first1=J. W. |last2=Adhikary |first2=D. |last3=Page |first3=J. T. |last4=Ramaraj |first4=T.|last5=Deyholos |first5=M. K. |last6=Udall |first6=J. A. |last7=Fairbanks |first7=D. J. |last8=Jellen |first8=E. N. |last9=Maughan |first9=P. J. |date=2016 |title=The Amaranth Genome: Genome, Transcriptome, and Physical Map Assembly |journal=The Plant Genome |volume=9 |issue=1 |pages=0 |doi=10.3835/plantgenome2015.07.0062 |pmid=27898770 |issn=1940-3372 |doi-access=free}}</ref>

The phylogenies of ''Amaranthus'' using [[Maximum parsimony (phylogenetics)|maximum parsimony]] and [[Bayesian inference|Bayesian]] analysis of [[Nuclear gene|nuclear]] and [[chloroplast]] [[gene]]s suggest five [[clade]]s within the genus: Diecious / Pumilus, Hybris, Galapagos, Eurasian/ South African, Australian (ESA), ESA + South American.<ref name=wasel/>

''Amaranthus'' includes three recognised subgenera and 75 species, although species numbers are questionable due to [[Hybrid (biology)|hybridisation]] and species concepts.<ref name=schmid/> Infrageneric classification focuses on inflorescence, flower characters and whether a species is monoecious/dioecious, as in the Sauer (1955) suggested classification.<ref name=stetter1/> Bracteole morphology present on the stem is used for taxonomic classification of Amaranth. Wild species have longer bracteoles compared to cultivated species.<ref name = "Costea" /> A modified infrageneric classification of ''Amaranthus'' includes three subgenera: ''[[Amaranthus tuberculatus|Acnida]]'', ''Amaranthus'', and ''Albersia'', with the taxonomy further differentiated by sections within each of the subgenera.<ref>{{cite journal |author1=Sergei L. Mosyakin |author2=Kenneth R. Robertson |year=1996 |title=New infrageneric taxa and combinations in ''Amaranthus'' (Amaranthaceae) |journal=Ann. Bot. Fennici |volume=33 |issue=4 |pages=275–281 |jstor=23726306}}</ref>

There is near certainty that ''[[Amaranthus hypochondriacus|A. hypochondriacus]]'' is the common ancestor to the cultivated grain species, however the later series of domestication to follow remains unclear. There has been opposing hypotheses of a single as opposed to multiple domestication events of the three grain species.<ref name=stetter1/><ref name="joshi">{{Cite journal |last1=Joshi |first1=Dinesh C. |last2=Sood |first2=Salej |last3=Hosahatti |first3=Rajashekara |last4=Kant |first4=Lakshmi |last5=Pattanayak |first5=A. |last6=Kumar |first6=Anil |last7=Yadav |first7=Dinesh |last8=Stetter |first8=Markus G. |date=2018-07-10 |title=From zero to hero: the past, present and future of grain amaranth breeding |journal=Theoretical and Applied Genetics |volume=131 |issue=9 |pages=1807–1823 |doi=10.1007/s00122-018-3138-y |pmid=29992369 |s2cid=49669284 |issn=0040-5752}}</ref> There is evidence of phylogenetic and geographical support for clear groupings that indicate separate domestication events in South America and Central America.<ref name=stetter1/> ''A.&nbsp;hybridus'' may derive from South America, whereas ''A.&nbsp;caudatus'', ''A.&nbsp;hypochondriacus'', and ''A.&nbsp;quentiensis'' are native to Central and North America.<ref name=stetter1/><ref name=joshi/>

=== Species ===
{{Main|List of Amaranthus species|l1 = List of ''Amaranthus'' species}}

Species include:<ref name="TPL">{{cite web |title=Search results—The Plant List |url=http://www.theplantlist.org/tpl/search?q=amaranthus |work=theplantlist.org}}</ref><ref>{{Cite journal |last1=Kumar |first1=Thaliyangal Rajesh |last2=Vishnu |first2=Walsan Kalarikkal |last3=Kumar |first3=Venugopalan Nair Saradamma Anil |last4=Arya |first4=Sindu |date=2019-05-13 |title=Amaranthus saradhiana (Amaranthaceae)—a new species from southern Western Ghats of Kerala, India |journal=Phytotaxa |language=en |volume=403 |issue=3 |pages=230–238 |doi=10.11646/phytotaxa.403.3.7 |issn=1179-3163 |s2cid=181814195}}</ref>

{{Div col|colwidth=30em}}
* ''[[Amaranthus acanthochiton]]'' – greenstripe
* ''Amaranthus acutilobus'' – a synonym of ''[[Amaranthus viridis]]''<ref name=TPL/>
* ''[[Amaranthus albus]]'' – white pigweed, tumble pigweed
* ''[[Amaranthus anderssonii]]''
* ''[[Amaranthus arenicola]]'' – sandhill amaranth
* ''[[Amaranthus australis]]'' – southern amaranth
* ''[[Amaranthus bigelovii]]'' – Bigelow's amaranth
* ''[[Amaranthus blitoides]]'' – mat amaranth, prostrate amaranth, prostrate pigweed
* ''[[Amaranthus blitum]]'' – purple amaranth
* ''[[Amaranthus brownii]]'' – Brown's amaranth
* ''[[Amaranthus californicus]]'' – California amaranth, California pigweed
* ''[[Amaranthus cannabinus]]'' – tidal-marsh amaranth
* ''[[Amaranthus caudatus]]'' – love-lies-bleeding, pendant amaranth, tassel flower, ''quilete''
* ''[[Amaranthus chihuahuensis]]'' – Chihuahuan amaranth
* ''[[Amaranthus crassipes]]'' – spreading amaranth
* ''[[Amaranthus crispus]]'' – crispleaf amaranth
* ''[[Amaranthus cruentus]]'' – purple amaranth, red amaranth, Mexican grain amaranth
* ''[[Amaranthus deflexus]]'' – large-fruit amaranth
* ''[[Amaranthus dubius]]'' – spleen amaranth, ''khada sag''
* ''[[Amaranthus fimbriatus]]'' – fringed amaranth, fringed pigweed
* ''[[Amaranthus floridanus]]'' – Florida amaranth
* ''[[Amaranthus furcatus]]''
* ''[[Amaranthus graecizans]]''
* ''[[Amaranthus grandiflorus]]''
* ''[[Amaranthus greggii]]'' – Gregg's amaranth
* ''[[Amaranthus hybridus]]'' – smooth amaranth, smooth pigweed, red amaranth
* ''[[Amaranthus hypochondriacus]]'' – Prince-of-Wales feather, prince's feather
* ''[[Amaranthus interruptus]]'' – Australian amaranth<ref>{{Cite web |title=Type of Amaranthus interruptus R.Br. [family AMARANTHACEAE] on JSTOR |url=https://plants.jstor.org/stable/10.5555/al.ap.specimen.bm000847082 |access-date=2020-10-08 |website=plants.jstor.org}}</ref>
* ''[[Amaranthus minimus]]''
* ''[[Amaranthus mitchellii]]''
* ''[[Amaranthus muricatus]]'' – African amaranth<ref>{{Cite web |title=Amaranthus muricatus (Moquin-Tandon) Hieronymus [family AMARANTHACEAE] on JSTOR |url=https://plants.jstor.org/stable/10.5555/al.ap.flora.fna004000844?searchUri=filter=name&so=ps_group_by_genus_species+asc&Query=Amaranthus+muricatus+ |access-date=2020-10-08 |website=plants.jstor.org}}</ref>
* ''[[Amaranthus obcordatus]]'' – Trans-Pecos amaranth
* ''[[Amaranthus palmeri]]'' – Palmer's amaranth, Palmer pigweed, careless weed
* ''[[Amaranthus polygonoides]]'' – tropical amaranth
* ''[[Amaranthus powellii]]'' – green amaranth, Powell amaranth, Powell pigweed
* ''[[Amaranthus pringlei]]'' – Pringle's amaranth
* ''[[Amaranthus pumilus]]'' – seaside amaranth
* ''[[Amaranthus quitensis]]'' - Mucronate Amaranth
* ''[[Amaranthus retroflexus]]'' – red-root amaranth, redroot pigweed, common amaranth
* ''[[Amaranthus saradhiana]]'' - purpal stem amaranth, green leaf amaranth
* ''Amaranthus scleranthoides'' – variously ''[[Amaranthus sclerantoides]]''
* ''[[Amaranthus scleropoides]]'' – bone-bract amaranth
* ''[[Amaranthus spinosus]]'' – spiny amaranth, prickly amaranth, thorny amaranth
* ''[[Amaranthus standleyanus]]''
* ''[[Amaranthus thunbergii]]'' – Thunberg's amaranth
* ''[[Amaranthus torreyi]]'' – Torrey's amaranth
* ''[[Amaranthus tricolor]]'' – Joseph's-coat
* ''[[Amaranthus tuberculatus]]'' – rough-fruit amaranth, tall waterhemp
* ''[[Amaranthus viridis]]'' – slender amaranth, green amaranth
* ''[[Amaranthus watsonii]]'' – Watson's amaranth
* ''[[Amaranthus wrightii]]'' – Wright's amaranth
{{div col end}}

=== Etymology ===
"Amaranth" derives from [[Ancient Greek|Greek]] {{lang|grc|ἀμάραντος}}<ref>{{LSJ|a)ma/rantos|ἀμάραντος|ref}}</ref> ({{lang|grc-Latn|amárantos}}), "unfading", with the Greek word for "flower", {{lang|grc|ἄνθος}} ({{lang|grc-Latn|ánthos}}), factoring into the word's development as ''amaranth, the unfading flower''. ''Amarant'' is an archaic variant. The name was first applied to the related ''[[Celosia]]'' (''Amaranthus'' and ''Celosia'' share long-lasting dried flowers), as ''Amaranthus'' plants were not yet known in Europe.<ref>{{Cite journal |last1=Costea |first1=Mihai |last2=Tardif |first2=François J. |date=2003 |title=The Name of the Amaranth: Histories of Meaning |journal=SIDA, Contributions to Botany |volume=20 |issue=3 |pages=1073–1083 |issn=0036-1488 |jstor=41968150}}</ref>