{{Short description|Genus of plants}} {{Automatic taxobox |image = Rumex X patientia Sturm55.jpg |image_caption = '''Patience dock'''<br/>(''Rumex patientia'') |taxon = Rumex |authority = L. 1753 |type_species = ''Rumex patientia'' |type_species_authority = L. |subdivision_ranks = Species |subdivision = About 200, see text |synonyms_ref = <ref name=POWO_328551-2/> |synonyms = {{Genus list |Acetosa|Tourn. ex Mill. |Acetosella|(Meisn.) Fourr. |Analiton|Raf. |Atecosa|Raf. |Bucephalophora|Pau |Centopodium|Burch. |Emex|Neck. ex Campd. |Eutralia|Raf. |Lapathon|Raf. |Lapathum|Mill. |Menophyla|Raf. |Nemolapathum|Ehrh. |Oxylapathon|St.-Lag. |Rhodoptera|Raf. |Steinmannia|Opiz |Tomaris|Raf. |Vibo|Medik. |Vibones|Raf. }} |}}

The '''docks''' and '''sorrels''', genus '''''Rumex''''', are a genus of about 200 species of annual, biennial, and perennial herbs in the buckwheat family, Polygonaceae.<ref name=POWO_328551-2/> Members of this genus are common perennial herbs with a worldwide native distribution in temperate and subtropical climates.<ref name=POWO_328551-2/>

Some are nuisance weeds (and are sometimes called dockweed or dock weed), but some are grown for their edible leaves.<ref>{{cite book |last=Martin |first=Alexander C. |title=Weeds |year=1972 |publisher=Golden Press |location=New York |isbn=0-307-24353-2 |page=[https://archive.org/details/weeds00mart/page/38 38] |url-access=registration |url=https://archive.org/details/weeds00mart/page/38}}</ref> ''Rumex'' species are used as food plants by the larvae of a number of Lepidoptera species, and are the only host plants of the butterflies ''Lycaena dispar'' and ''Lycaena rubidus.''<ref>{{Cite journal|last1=Warren|first1=Andres|last2=Harrera|first2=Alfonso|date=15 March 2005|title=Butterflies of Oregon Their Taxonomy, Distribution, and Biology|url=https://dspace.library.colostate.edu/bitstream/handle/10217/81121/BSPMGILL_LepidopteraofNorthAmerica6.pdf?sequence=1|journal=Lepidoptera of North America|volume=6}}</ref>

==Etymology== ''Rumex'' is from the Latin, meaning to suck, alluding to the practice since Roman times of sucking the leaves to alleviate thirst.<ref name=POWO_328551-2/> The name dock is from the Old English ''docce'', meaning tall weed, and other European languages for ''bundle'' or ''tuft''.<ref>{{cite web|url=https://www.etymonline.com/word/dock| title=Dock (n.3)|publisher=Online Etymology Dictionary|date=2026|access-date=6 February 2026}}</ref>

==Description== They are erect plants, usually with long taproots.<ref name=POWO_328551-2/> The fleshy to leathery leaves form a basal rosette at the root. The basal leaves may be different from those near the inflorescence. They may or may not have stipules. Minor leaf veins occur. The leaf blade margins are entire or crenate.{{cn|date=September 2025}}

The usually inconspicuous flowers are carried above the leaves in clusters. The fertile flowers are mostly hermaphrodites, or they may be functionally male or female. The flowers and seeds grow on long clusters at the top of a stalk emerging from the basal rosette; in many species, the flowers are green, but in some (such as sheep's sorrel, ''Rumex acetosella'') the flowers and their stems may be brick-red. Each seed is a three-sided achene, often with a round tubercle on one or all three sides.{{cn|date=September 2025}}

==Taxonomy== The genus was first described by Carl Linnaeus in 1753. Within the family Polygonaceae, it is placed in the subfamily Polygonoideae. The genus ''Emex'' was separated from ''Rumex'' by Francisco Campderá in 1819 on the basis that it was polygamous (i.e. had both bisexual and unisexual flowers on the same plant). However, some species of ''Rumex'' subg. ''Acetosa'' also have this characteristic, and most other features that are supposed to distinguish ''Emex'' are found in species of ''Rumex''. Accordingly, in 2015, Schuster et al. demoted ''Emex'' to a subgenus of ''Rumex''.<ref name=SchuReveBaylKron15>{{Citation |mode=cs1|last1=Schuster |first1=Tanja M. |last2=Reveal |first2=James L. |last3=Bayly |first3=Michael J. |last4=Kron |first4=Kathleen A. |date=2015 |title=An updated molecular phylogeny of Polygonoideae (Polygonaceae): Relationships of ''Oxygonum'', ''Pteroxygonum'', and ''Rumex'', and a new circumscription of ''Koenigia'' |journal=Taxon |volume=64 |issue=6 |pages=1188–1208 |doi=10.12705/646.5 |bibcode=2015Taxon..64.1188S |name-list-style=amp}}</ref>

Within the subfamily Polygonoideae, ''Rumex'' is placed in the tribe Rumiceae, along with the two genera ''Oxyria'' and ''Rheum''. It is most closely related to ''Rheum'', which includes Rhubarb.<ref name=SchuReveBaylKron15/> {{clade |label1=Rumiceae |1={{clade |1=''Oxyria'' |2={{clade |1=''Rumex'' |2=''Rheum'' }} }} }}

===Species=== thumb|''Rumex nervosus'' in Ethiopia right|thumb|Broad-leaved dock leaves (''R.&nbsp;obtusifolius'') thumb|Flowers of curled dock (''R.&nbsp;crispus'') with remarkable tubercles {{As of|2022|June}}, Plants of the World Online accepted the following species. A large number of hybrids are also recorded.<ref name="POWO_328551-2">{{cite web |title=''Rumex'' <small>L.</small> |work=Plants of the World Online |publisher=Royal Botanic Gardens, Kew|url=https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:328551-2 |access-date=6 February 2026|date=2026}}</ref> {{div col|colwidth=25em}} *''Rumex abyssinicus'' <small>Jacq.</small> *''Rumex acetosa'' <small>L.</small> – sorrel, common sorrel, garden sorrel, narrow-leaved dock, spinach dock *''Rumex acetosella'' <small>L.</small> – sheep's sorrel, common sheep sorrel, field sorrel, red sorrel *''Rumex aegyptiacus'' <small>L.</small> *''Rumex aeroplaniformis'' <small>Eig</small> *''Rumex albescens'' <small>Hillebr.</small> – Oahu dock *''Rumex alcockii'' <small>Rech.f.</small> *''Rumex algeriensis'' <small>Barratte & Murb.</small> *''Rumex alpinus'' <small>L.</small> – alpine dock, monk's rhubarb *''Rumex altissimus'' <small>Alph.Wood</small> – pale dock, smooth dock, peach-leaf dock *''Rumex alveolatus'' <small>Losinsk.</small> *''Rumex amanus'' <small>Rech.f.</small> *''Rumex amurensis'' <small>F.Schmidt ex Maxim</small> *''Rumex andinus'' <small>Rech.f.</small> *''Rumex angulatus'' <small>Rech.f.</small> *''Rumex angustifolius'' <small>Campd.</small> *''Rumex aquaticiformis'' <small>Rech.f.</small> *''Rumex aquaticus'' <small>L.</small> – western dock, Scottish dock<!-- BiolConserv137:248. --> *''Rumex aquitanicus'' <small>Rech.f.</small> *''Rumex arcticus'' <small>Trautv.</small> *''Rumex arcuatoramosus'' <small>Rech.f.</small> *''Rumex argentinus'' <small>Rech.f.</small> *''Rumex arifolius'' <small>All.</small> *''Rumex aristidis'' <small>Coss.</small> *''Rumex armenus'' <small>K.Koch</small> *''Rumex atlanticus'' <small>Coss. ex Batt.</small> *''Rumex aureostigmatica'' <small>Kom.</small> *''Rumex azoricus'' <small>Rech.f.</small> *''Rumex balcanicus'' <small>Rech.f.</small> *''Rumex beringensis'' <small>Jurtzev & V.V.Petrovsky</small> – Bering Sea dock *''Rumex bidens'' <small>R.Br.</small> *''Rumex bipinnatus'' <small>L.f.</small> *''Rumex bithynicus'' <small>Rech.f.</small> *''Rumex brachypodus'' <small>Rech.f.</small> *''Rumex brasiliensis'' <small>Link</small> *''Rumex britannica'' <small>L.</small> *''Rumex brownii'' <small>Campd.</small> – Browne's dock *''Rumex bryhnii'' <small>Snogerup</small> *''Rumex bucephalophorus'' <small>L.</small> – red dock *''Rumex californicus'' <small>Rech.f.</small> *''Rumex caucasicus'' <small>Rech.f.</small> *''Rumex chalepensis'' <small>Mill.</small> *''Rumex chrysocarpos'' <small>Moris</small> *''Rumex confertus'' <small>Willd.</small> – Asiatic dock *''Rumex conglomeratus'' <small>Murray</small> – clustered dock, sharp dock *''Rumex cordatus'' <small>Poir.</small> *''Rumex costaricensis'' <small>Rech.f.</small> *''Rumex crassus'' <small>Rech.f.</small> *''Rumex crispellus'' <small>Rech.f.</small> *''Rumex crispissimus'' <small>Kuntze</small> *''Rumex crispus'' <small>L.</small> – curled dock, curly dock, yellow dock, sour dock, narrow dock, garden patience, narrow-leaved dock *''Rumex cristatus'' <small>DC.</small> *''Rumex crystallinus'' <small>Lange</small> – shiny dock *''Rumex cuneifolius'' <small>Campd.</small> *''Rumex cyprius'' <small>Murb.</small> *''Rumex darwinianus'' <small>Rech.f.</small> *''Rumex densiflorus'' <small>Osterh.</small> – dense-flower dock, dense-flowered dock *''Rumex dentatus'' <small>L.</small> – toothed dock *''Rumex dregeanus'' <small>Meisn.</small> *''Rumex drummondii'' <small>Meisn.</small> *''Rumex dumosus'' <small>A.Cunn. ex Meisn.</small> – wiry dock *''Rumex elbrusensis'' <small>Boiss.</small> *''Rumex ellipticus'' <small>Greene</small> *''Rumex ephedroides'' <small>Bornm.</small> *''Rumex evenkiensis'' <small>Elis.</small> *''Rumex fascicularis'' <small>Small</small> *''Rumex fischeri'' <small>Rchb.</small> *''Rumex flexicaulis'' <small>Rech.f.</small> *''Rumex flexuosus'' <small>Sol. ex G.Forst.</small> *''Rumex floridanus'' <small>Meisn.</small> *''Rumex frutescens'' <small>Thouars</small> – wedgeleaf dock *''Rumex fueginus'' <small>Phil.</small> *''Rumex gangotrianus'' <small>Aswal & S.K.Srivast.</small> *''Rumex garipensis'' <small>Meisn.</small> *''Rumex giganteus'' <small>W.T.Aiton</small> – pawale *''Rumex ginii'' <small>Jahandiez & Maire</small> *''Rumex gmelinii'' <small>Turcz. ex Ledeb.</small> *''Rumex gracilescens'' <small>Rech.f.</small> *''Rumex graminifolius'' <small>Georgi ex Lamb.</small> – grassleaf sorrel *''Rumex hastatulus'' <small>Baldwin</small> – heartwing dock, heartwing sorrel *''Rumex hastatus'' <small>D.Don</small> *''Rumex hesperius'' <small>Greene</small> *''Rumex hultenii'' <small>Tzvelev</small> *''Rumex hydrolapathum'' <small>Huds.</small> – great water dock *''Rumex hymenosepalus'' <small>Torr.</small> – canaigre, canaigre dock *''Rumex hypogaeus'' <small>T.M.Schust. & Reveal</small> *''Rumex inconspicuus'' <small>Rech.f.</small> *''Rumex induratus'' <small>Boiss. & Reut.</small> *''Rumex intermedius'' <small>DC.</small> *''Rumex jacutensis'' <small>Kom.</small> *''Rumex japonicus'' <small>Houtt.</small> *''Rumex kandavanicus'' <small>(Rech.f.) Rech.f.</small> *''Rumex kerneri'' <small>Borbás</small> – Kerner's dock *''Rumex komarovii'' <small>Schischk. & Serg.</small> *''Rumex krausei'' <small>Jurtzev & V.V.Petrovsky</small> – Krause's sorrel *''Rumex lacustris'' <small>Greene</small> *''Rumex lanceolatus'' <small>Thunb.</small> *''Rumex lapponicus'' <small>(Hiitonen) Czernov</small> *''Rumex lativalvis'' <small>Meisn.</small> *''Rumex leptocaulis'' <small>Brandbyge & Rech.f.</small> *''Rumex limoniastrum'' <small>Jaub. & Spach</small> *''Rumex longifolius'' <small>DC.</small> – dooryard dock, northern dock *''Rumex lorentzianus'' <small>Lindau</small> *''Rumex lunaria'' <small>L.</small> *''Rumex madaio'' <small>Makino</small> *''Rumex maderensis'' <small>Lowe</small> *''Rumex magellanicus'' <small>Campd.</small> *''Rumex maricola'' <small>J.Rémy</small> *''Rumex maritimus'' <small>L.</small> – golden dock, bristle dock, seashore dock *''Rumex marschallianus'' <small>Rchb.</small> *''Rumex mexicanus'' <small>Meisn.</small> *''Rumex microcarpus'' <small>Campd.</small> *''Rumex nebroides'' <small>Campd.</small>

*''Rumex neglectus'' <small>Kirk</small>g *''Rumex nematopodus'' <small>Rech.f.</small> – Arizona dock *''Rumex nepalensis'' <small>Spreng.</small> *''Rumex nervosus'' <small>Vahl</small> *''Rumex nivalis'' <small>Hegetschw.</small> *''Rumex oblongifolius'' <small>Tolm.</small> *''Rumex obovatus'' <small>Danser</small> – tropical dock *''Rumex obtusifolius'' <small>L.</small> – broad-leaved dock, bitter dock, bluntleaf dock, butter dock *''Rumex occidentalis'' <small>S.Watson</small> *''Rumex occultans'' <small>Sam.</small> *''Rumex olympicus'' <small>Boiss.</small> *''Rumex orbiculatus'' <small>A.Gray</small> – great water dock *''Rumex orthoneurus'' <small>Rech.f.</small> – Chiricahua mountain dock *''Rumex pallidus'' <small>Bigelow</small> – seaside dock *''Rumex palustris'' <small>Sm.</small> – marsh dock *''Rumex papilio'' <small>Coss. & Balansa</small> *''Rumex papillaris'' <small>Boiss. & Reut.</small> *''Rumex paraguayensis'' <small>D.Parodi</small> – Paraguayan dock *''Rumex patagonicus'' <small>Rech.f.</small> *''Rumex patientia'' <small>L.</small> – patience dock, garden patience, monk's rhubarb *''Rumex paucifolius'' <small>Nutt.</small> – alpine sheep's sorrel, few-leaved dock, meadow dock *''Rumex paulsenianus'' <small>Rech.f.</small> *''Rumex persicarioides'' <small>L.</small> *''Rumex peruanus'' <small>Rech.f.</small> *''Rumex pictus'' <small>Forssk.</small> *''Rumex polycarpus'' <small>Rech.f.</small> *''Rumex ponticus'' <small>E.H.L.Krause</small> *''Rumex popovii'' <small>Pachom.</small> *''Rumex praecox'' <small>Rydb.</small> *''Rumex pseudonatronatus'' <small>(Borbás) Murb.</small> – field dock *''Rumex pseudoxyria'' <small>(Tolm.) Khokhr.</small> *''Rumex pulcher'' <small>L.</small> – fiddle dock *''Rumex punjabensis'' <small>K.M.Vaid & H.B.Naithani</small> *''Rumex pycnanthus'' <small>Rech.f.</small> *''Rumex rectinervius'' <small>Rech.f.</small> *''Rumex rhodesius'' <small>Rech.f.</small> *''Rumex romassa'' <small>Remy</small> *''Rumex roseus'' <small>L.</small> *''Rumex rossicus'' <small>Murb.</small> *''Rumex rugosus'' <small>Campd.</small> *''Rumex rupestris'' <small>Le Gall</small> – shore dock *''Rumex ruwenzoriensis'' <small>Chiov.</small> *''Rumex sagittatus'' <small>Thunb.</small> *''Rumex salicifolius'' <small>Weinm.</small> – willow dock, willow-leaved dock *''Rumex sanguineus'' <small>L.</small> – wood dock, redvein dock<!-- BiolConserv137:248. --> *''Rumex scutatus'' <small>L.</small> – French sorrel, leaf-shield sorrel *''Rumex sellowianus'' <small>Rech.f.</small> *''Rumex sibiricus'' <small>Hultén</small> – Siberian dock *''Rumex similans'' <small>Rech.f.</small> *''Rumex simpliciflorus'' <small>Murb.</small> *''Rumex skottsbergii'' <small>O.Deg. & I.Deg.</small> – lava dock *''Rumex songaricus'' <small>Fisch. & C.A.Mey.</small> *''Rumex spathulatus'' <small>Thunb.</small> *''Rumex spinosus'' <small>L.</small> *''Rumex spiralis'' <small>Small</small> – winged dock *''Rumex stenoglottis'' <small>Rech.f.</small> *''Rumex stenophyllus'' <small>Ledeb.</small> *''Rumex subarcticus'' <small>Lepage</small> *''Rumex suffruticosus'' <small>J.Gay ex Meisn.</small> *''Rumex tenax'' <small>Rech.f.</small> *''Rumex thjanschanicus'' <small>Losinsk.</small> *''Rumex thyrsiflorus'' <small>Fingerh.</small> *''Rumex thyrsoides'' <small>Desf.</small> *''Rumex tmoleus'' <small>Boiss.</small> *''Rumex tolimensis'' <small>Wedd.</small> *''Rumex transitorius'' <small>Rech.f.</small> *''Rumex triangulivalvis'' <small>(Danser) Rech.f.</small> *''Rumex trisetifer'' <small>Stokes</small> *''Rumex tuberosus'' <small>L.</small> *''Rumex tunetanus'' <small>Barratte & Murb.</small> *''Rumex turcomanicus'' <small>(Rech.f.) Czerep.</small> *''Rumex ucranicus'' <small>Fisch. ex Spreng.</small> *''Rumex ujskensis'' <small>Rech.f.</small> *''Rumex uruguayensis'' <small>Rech.f.</small> *''Rumex usambarensis'' <small>(Engl.) Dammer</small> *''Rumex utahensis'' <small>Rech.f.</small> *''Rumex venosus'' <small>Pursh</small> – veiny dock, sand dock *''Rumex verticillatus'' <small>L.</small> – swamp dock, water dock *''Rumex vesicarius'' <small>L.</small> – bladder dock *''Rumex violascens'' <small>Rech.f.</small> – violet dock *''Rumex woodii'' <small>N.E.Br.</small> *''Rumex yungningensis'' <small>Sam.</small> {{div col end}}

==Uses== {{nutritional value | name=Dock, raw (''Rumex'' spp.) |water=93 g | kJ=92 | protein=2 g | fat=0.7 g | carbs=3.2 g | fiber=2.9 g | calcium_mg=44 | iron_mg=2.4 | magnesium_mg=103 | phosphorus_mg=63 | potassium_mg=390 | zinc_mg=0.2 | manganese_mg=0.349 | vitC_mg=48 | thiamin_mg=0.04 | riboflavin_mg=0.1 | niacin_mg=0.5 | vitB6_mg=0.122 | folate_ug=13 | vitA_ug=200 | note=[https://fdc.nal.usda.gov/food-details/170076/nutrients Link to USDA Database entry] }}

Broad-leaved dock (''Rumex obtusifolius'') used to be called butter dock because its large leaves were used to wrap and conserve butter.

These plants are edible. The leaves of most species contain oxalic acid and tannin, and many have astringent and slightly purgative qualities. Some species with particularly high levels of oxalic acid are called sorrels (including sheep's sorrel ''Rumex acetosella'', common sorrel ''Rumex acetosa'', and French sorrel ''Rumex scutatus''), and some of these are grown as leaf vegetables or garden herbs for their acidic taste.<ref>{{cite web |url=http://www.botanical.com/botanical/mgmh/s/sorcom64.html |title=Sorrel, Garden or Common [''Rumex acetosa''] |website=Botanical.com}}</ref><ref>{{cite journal | journal = Journal of Ethnobiology and Ethnomedicine | year = 2008 | volume = 4 | issue = 1 | doi = 10.1186/1746-4269-4-4 |pmc=2275233 | title = Archival data on wild food plants used in Poland in 1948 | first = Łukasz | last = Łuczaj | article-number = 4 | pmid = 18218132 | doi-access = free }}</ref>

In the United Kingdom, ''Rumex obtusifolius'' is often found growing near stinging nettles, owing to both species favouring a similar environment, and there is a widely held belief that the underside of the dock leaf, squeezed to extract a little juice, can be rubbed on the skin to counteract the itching caused by brushing against a nettle plant.<ref>{{cite web |work=Ethnomedica |url=http://www.rbgkew.org.uk/ethnomedica/reports/dock.html |title=Recorded uses of' dock (''Rumex'' sp.) |access-date=2008-04-15 |url-status=usurped |archive-url=https://web.archive.org/web/20081120040109/http://www.rbgkew.org.uk/ethnomedica/reports/dock.html |archive-date=2008-11-20}} {{verify source |date=September 2019}}</ref> This home remedy is not supported by any science, although it is possible that the act of rubbing may act as a distracting counterstimulation, or that belief in the dock's effect may provide a placebo effect.<ref>{{cite news |last1=Hopcroft |first1=Keith |title=Home remedies: dock leaves for nettle stings |url=https://www.thetimes.com/article/home-remedies-dock-leaves-for-nettle-stings-gk075bw6b3c |access-date=29 August 2020 |date=10 September 2005 |language=en}}</ref>

===Nutrition=== Raw dock is 93% water, 3% carbohydrates, 2% protein, and 1% fat (table). In a reference amount of {{cvt|100|g}}, it supplies 22 calories and rich amounts (more than 20% of the Daily Value, DV) of vitamin C, vitamin A, and magnesium, with moderate content of several dietary minerals (table).

==Fossil record== Several fossil fruits of ''Rumex'' sp. have been described from middle Miocene strata of the Fasterholt area near Silkeborg in Central Jutland, Denmark.<ref>{{cite journal |title=Angiosperm Fruits and Seeds from the Middle Miocene of Jutland (Denmark) |first=Else Marie |last=Friis |author-link=Else Marie Friis |journal=The Royal Danish Academy of Sciences and Letters |volume=24 |issue=3 |year=1985}}</ref> One fossil fruit of a ''Rumex'' species has been extracted from a borehole sample of the Middle Miocene fresh water deposits in Nowy Sacz Basin, West Carpathians, Poland. This fossil fruit is similar to the fruits of the extant species ''Rumex maritimus'' and ''Rumex ucranicus'' which both have fossil records from the Pliocene and Pleistocene of Europe.<ref>Macroscopic plant remains from the freshwater Miocene of the Nowy Sącz Basin (West Carpathians, Poland) by Maria Łańcucka-Środoniowa, Acta Palaeobotanica 1979 20 (1): 3-117.</ref>

==References== {{Reflist}}

==External links== {{Commons category|Rumex}} {{Wikispecies}} *[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=242414256 Rumex acetosella]; Missouri Botanical Garden's efloras.org. *[http://www.northernbushcraft.com/plants/dock/notes.htm Edibility of Dock]: Identification and edible parts of Rumex spp. * {{cite web| url= http://www.ville-ge.ch/musinfo/bd/cjb/africa/resultat.php?efNom=Rumex&efFamille=&projet%5B%5D=FSA&projet%5B%5D=FTA&projet%5B%5D=FNA&projet%5B%5D=BDM&langue=an&pbRecherche=Search| title= Rumex | access-date= 2018-07-05| work= African Plants Database| publisher= Conservatoire et Jardin botaniques & South African National Biodiversity Institute}} * {{cite book|last=Linnæi|first=Caroli|author-link=Carl Linnaeus|title=Species Plantarum, Exhibentes Plantas Rite Cognitas, ad Genera Relatas, cum Differenentiis Specificis, Nominibus Trivialibus, Synonymis Selectis, Locis Natalibus, Secundum System Sexuale Digestas|url=http://www.botanicus.org/title/b12069590|access-date=2008-07-02|year = 1753 | chapter = Trigynia | chapter-url = http://www.botanicus.org/page/358352}}

{{Taxonbar|from1=Q157264|from2=Q15926219|from3=Q32252794|from4=Q32254567|from5=Q1632348|from6=Q15928071}} {{Authority control}}

Category:Rumex Category:Polygonaceae genera Category:Botanical taxa named by Carl Linnaeus Category:Taxa described in 1753