Editing Oxalis

{{Short description|Genus of flowering plants}}
{{Other uses}}
{{Automatic taxobox
|image=TAU-2013-Oxalis 0039a-ZachiEvenor.jpg
|image_caption=''[[Oxalis pes-caprae]]''
|taxon=Oxalis
|authority=[[Carl Linnaeus|L.]]
|subdivision_ranks=[[Species]]
|subdivision=About 550, see [[List of Oxalis species|List of ''Oxalis'' species]]
}}

'''''Oxalis''''' ({{IPAc-en|ˈ|ɒ|k|s|ə|l|ᵻ|s}} (American English)<ref>''Sunset Western Garden Book,'' 1995:606–607</ref> or {{IPAc-en|ɒ|k|s|'|ɑː|l|ᵻ|s}} (British English))<ref>{{Cite web |url=https://www.lexico.com/en/definition/oxalis |title=Oxalis &#124; Definition of Oxalis by Oxford Dictionary on Lexico.com also meaning of Oxalis |website=Lexico Dictionaries &#124; English |access-date=2019-06-12 |archive-date=2021-06-12 |archive-url=https://web.archive.org/web/20210612062538/https://www.lexico.com/en/definition/oxalis |url-status=dead }}</ref> is a large [[genus]] of [[flowering plant]]s in the wood-sorrel family, [[Oxalidaceae]], comprising over 550 species.<ref name="Christenhusz-Byng2016">{{cite journal |author1=Christenhusz, M. J. M. |author2=Byng, J. W. |year=2016 |title=The number of known plants species in the world and its annual increase |journal=Phytotaxa |volume=261 |pages=201–217 |url=http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598 |doi=10.11646/phytotaxa.261.3.1 |issue=3 |doi-access=free |bibcode=2016Phytx.261..201C |access-date=2017-12-21 |archive-date=2016-07-29 |archive-url=https://web.archive.org/web/20160729085754/http://biotaxa.org/Phytotaxa/article/download/phytotaxa.261.3.1/20598 |url-status=live }}</ref> The genus occurs throughout most of the world, except for the [[Polar region|polar]] areas; species diversity is particularly rich in tropical [[Brazil]], [[Mexico]], and [[South Africa]].

Many of the species are known as '''wood sorrels''' (sometimes written "woodsorrels" or "wood-sorrels") as they have an acidic taste reminiscent of the sorrel proper (''[[Rumex acetosa]]''), which is not closely related. Some species are called '''yellow sorrels''' or '''pink sorrels''' after the color of their flowers instead. Other species are colloquially known as '''false [[shamrock]]s''', and some called '''[[sourgrass]]es'''. For the genus as a whole, the term '''oxalises''' is also used.

==Description==
[[File:Oxalis floral diagram.jpg|thumb|[[Floral diagram]] of ''Oxalis'']]
The plants are [[annual plant|annual]] or [[perennial]]. The leaves are divided into three to ten or more obovate and top-notched leaflets, arranged palmately with all the leaflets of roughly equal size. The majority of species have three leaflets, superficially similar to those of some [[clover]]s.<ref>{{Cite web |url=https://plants.ces.ncsu.edu/plants/all/oxalis/ |title=Oxalis |website=NC State University |access-date=2018-09-20 |archive-date=2021-09-01 |archive-url=https://web.archive.org/web/20210901071510/https://plants.ces.ncsu.edu/plants/oxalis/ |url-status=live }}</ref> Some species exhibit rapid changes in leaf angle in response to temporarily high light intensity to decrease [[photoinhibition]].<ref>{{Cite journal |title=Photosynthesis and photoinhibition in two differently coloured varieties of Oxalis triangularis — the effect of anthocyanin content |journal=Photosynthetica |volume=49 |issue=3 |pages=346–352 |last=S. L. Nielsen, A. M. Simonsen |date=September 2011 |doi=10.1007/s11099-011-0042-y |s2cid=24583290|doi-access=free |bibcode=2011Phsyn..49.0042N }}</ref>

The flowers have five petals, which are usually fused at the base, and ten [[stamen]]s. The petal color varies from white to pink, red or yellow;<ref>{{Cite web |url=https://wimastergardener.org/article/shamrocks-oxalis-spp/ |title=Shamrocks, Oxalis spp. |last=Mahr |first=Susan |date=March 2009 |website=Master Gardener Program University of Wisconsin-Extension |access-date=2018-09-20 |archive-date=2018-09-21 |archive-url=https://web.archive.org/web/20180921034823/https://wimastergardener.org/article/shamrocks-oxalis-spp/ |url-status=live }}</ref> [[anthocyanin]]s and [[xanthophyll]]s may be present or absent but are generally not both present together in significant quantities, meaning that few wood-sorrels have bright orange flowers. The fruit is a small [[Capsule (fruit)|capsule]] containing several seeds. The roots are often tuberous and succulent, and several species also <!--also? do any species produce bulbils as well as tubers?--> reproduce vegetatively by production of [[bulbil]]s, which detach to produce new plants.

== Ecology ==
[[Image:Oxalis acetosella jfg.jpg|thumb|Common wood sorrel (''[[Oxalis acetosella]]'')]]
[[File:Lyc oviposit.jpg|thumb|right|Pale grass blue (''[[Pseudozizeeria maha]]'') of the dry-season brood laying eggs on ''Oxalis'']]
Several ''Oxalis'' species dominate the plant life in local woodland ecosystems, be it [[Coast Range (EPA ecoregion)|Coast Range ecoregion]] of the [[North America]]n [[Pacific Northwest]], or the [[Sydney Turpentine-Ironbark Forest]] in southeastern Australia where least yellow sorrel (''[[Oxalis exilis|O. exilis]]'') is common. In the United Kingdom and neighboring Europe, common wood sorrel (''[[Oxalis acetosella|O. acetosella]]'') is the typical woodland member of this genus, forming large swaths in the typical mixed deciduous forests dominated by downy birch (''[[Betula pubescens]]'') and sessile oak (''[[Quercus petraea]]''), by sycamore maple (''[[Acer pseudoplatanus]]''), [[Bracken|common bracken]] (''Pteridium aquilinum''), pedunculate oak (''[[Quercus robur|Q. robur]]'') and [[blackberries]] (''Rubus fruticosus'' agg.), or by common ash (''[[Fraxinus excelsior]]''), [[dog's mercury]] (''Mercurialis perennis'') and European rowan (''[[Sorbus aucuparia]]''); it is also common in woods of common juniper (''[[Juniperus communis]]'' ssp. ''communis''). Some species &ndash; notably [[Oxalis pes-caprae|Bermuda-buttercup]] (''O.&nbsp;pes-caprae'') and [[Oxalis corniculata|creeping woodsorrel]] (''O.&nbsp;corniculata'') &ndash; are pernicious, invasive weeds when escaping from cultivation outside their native ranges; the ability of most wood-sorrels to store reserve energy in their tubers makes them quite resistant to most weed control techniques.

A 2019 study<ref>{{Cite journal |last1=Jooste |first1=Michelle |last2=Roets |first2=Francois |last3=Midgley |first3=Guy F. |last4=Oberlander |first4=Kenneth C. |last5=Dreyer |first5=Léanne L. |date=2019-10-23 |title=Nitrogen-fixing bacteria and Oxalis – evidence for a vertically inherited bacterial symbiosis |journal=BMC Plant Biology |volume=19 |issue=1 |pages=441 |doi=10.1186/s12870-019-2049-7 |issn=1471-2229 |pmc=6806586 |pmid=31646970 |doi-access=free |bibcode=2019BMCPB..19..441J }}</ref> suggested that species from this [[genus]] have a symbiotic relationship with nitrogen fixing [[Bacillus|''Bacillus'' endophytes]], storing them in plant tissues and seeds, which could explain its ability to spread rapidly even in poor soils.

Tuberous woodsorrels provide food for certain small [[herbivore]]s &ndash; such as the [[Montezuma quail]] (''Cyrtonyx montezumae''). The foliage is eaten by some [[Lepidoptera]], such as the [[Polyommatini]] [[pale grass blue]] (''Pseudozizeeria maha'') &ndash; which feeds on creeping wood sorrel and others &ndash; and [[Zizeeria lysimon|dark grass blue]] (''Zizeeria lysimon'').

''Oxalis'' species are susceptible to [[rust (fungus)|rust]] (''[[Puccinia oxalidis]]'').

[[File:Close-up of an 'apricot' NZ yam.JPG|thumb|An apricot-coloured variety of ''[[Oxalis tuberosa]]'' for eating]]
[[File:Oca.jpg|thumb|right|Some [[oxalis tuberosa|oca]]]]
[[File:2007-07-01Oxalis tetraphylla04.jpg|thumb|right|[[Four-leaved pink-sorrel]] (''[[Oxalis tetraphylla|O. tetraphylla]]'') grown as a [[pot plant]]]]
==Uses==

===As food===
Wood sorrel (a type of oxalis) is an edible wild plant that has been consumed by humans around the world for millennia.<ref name="autogenerated2">{{Cite book |last=Duke |first=James A. |url=https://books.google.com/books?id=rVrteo-8cI0C |title=Handbook of Edible Weeds: Herbal Reference Library |date=2000-11-10 |publisher=CRC Press |isbn=978-0-8493-2946-3 |language=en}}</ref> In Dr. James Duke's ''Handbook of Edible Weeds,'' he notes that the Native American [[Kiowa]] people chewed wood sorrel to alleviate thirst on long trips, the [[Potawatomi]] cooked it with sugar to make a dessert, the [[Algonquin people|Algonquin]] considered it an [[aphrodisiac]], the Cherokee ate wood sorrel to alleviate mouth sores and a sore throat, and the [[Iroquois]] ate wood sorrel to help with cramps, fever and nausea.<ref name="autogenerated2" />

The fleshy, juicy edible [[tuber]]s of the [[Oxalis tuberosa|oca]] (''O. tuberosa'') have long been cultivated for food in [[Colombia]] and elsewhere in the northern [[Andes mountains]] of [[South America]]. It is grown and sold in [[New Zealand]] as "New Zealand yam" (although not a true yam), and varieties are now available in yellow, orange, apricot, and pink, as well as the traditional red-orange.<ref>{{Cite web |url=https://www.vegetables.co.nz/vegetables-a-z/yams/ |title=Yams |website=Vegetables |access-date=2021-01-17 |archive-date=2021-01-20 |archive-url=https://web.archive.org/web/20210120073510/https://www.vegetables.co.nz/vegetables-a-z/yams/ |url-status=live }}</ref>

The leaves of scurvy-grass sorrel (''O. enneaphylla'') were eaten by [[sailor]]s travelling around [[Patagonia]] as a source of [[vitamin C]] to avoid [[scurvy]].

In [[India]], creeping wood sorrel (''O. corniculata'') is eaten only seasonally, starting in December–January. The [[Bodo people|Bodos]] of north east India sometimes prepare a sour fish curry with its leaves. The leaves of common wood sorrel (''[[Oxalis acetosella|O. acetosella]]'') may be used to make a lemony-tasting tea when dried.

===Other uses===
[[File:Oxalis versicolor (candycane sorrel).jpg|thumb|right|''[[Oxalis versicolor]]'' (candycane sorrel) grown in New Zealand]]

In the past, it was a practice to extract crystals of [[calcium oxalate]] for use in treating diseases and as a [[Salt (chemistry)|salt]] called ''sal acetosella'' or [[Potassium hydrogenoxalate|"sorrel salt"]] (also known as "salt of lemon"). Growing oca tuber [[root cap]]s are covered in a [[fluorescent]] slush rich in [[harmaline]] and [[harmine]] which apparently suppresses [[Pest (organism)|pest]]s.<ref>Bais ''et al.'' (2002, 2003)</ref> Creeping wood sorrel and perhaps other species are apparently [[hyperaccumulator]]s of [[copper]]. The [[Ming Dynasty]] text ''Precious Secrets of the Realm of the King of Xin'' from 1421 describes how ''O.&nbsp;corniculata'' can be used to locate copper deposits as well as for [[geobotanical prospecting]]. It thus ought to have some potential for [[phytoremediation]] of contaminated soils.{{Citation needed|date=January 2022}}[[File:Double-flowered Oxalis compressa.JPG|thumb|Double-flowered ''[[Oxalis compressa]]'']]
==As ornamental plants==
[[File:Dreieckiger Glücksklee (Oxalis triangularis) (19067830888).jpg|thumb|''[[Oxalis triangularis]]'']]
Several species are grown as [[pot plant]]s or as [[ornamental plant]]s in [[garden]]s, for example, ''O. versicolor''.

Oxalis flowers range in colour from whites to yellow, peaches, pink, or multi-coloured flowers.<ref>{{Cite web|url=http://www.stuff.co.nz/nelson-mail/lifestyle-entertainment/lifestyle/home-and-garden/2495449/A-daring-passion|title=A daring passion|date=28 August 2009|access-date=25 July 2014|archive-date=27 July 2014|archive-url=https://web.archive.org/web/20140727203727/http://www.stuff.co.nz/nelson-mail/lifestyle-entertainment/lifestyle/home-and-garden/2495449/A-daring-passion|url-status=live}}</ref>

Some varieties have double flowers, for example the double form of ''O. compressus''. Some varieties are grown for their foliage, such as the dark purple-leaved ''O.&nbsp;triangularis''.

Species with four regular leaflets &ndash; in particular ''[[Oxalis tetraphylla|O. tetraphylla]]'' (four-leaved pink-sorrel) &ndash; are sometimes misleadingly sold as "four-leaf [[clover]]", taking advantage of the mystical status of [[four-leaf clover]].

==Selected species==
{{Main|List of Oxalis species|l1=List of ''Oxalis'' species}}

[[Image:Oxalis arborea1.jpg|thumb|right|''[[Oxalis articulata]]'' Savign. forma ''crassipes'' (Urb.) Lourteig, 1982]]
[[Image:Oxalis corymbosa - flower view 01.jpg|thumb|right|''[[Oxalis corymbosa]]'']]
[[Image:(MHNT) Oxalis articulata - Habit.jpg|thumb|right|''[[Oxalis articulata]]'' Savign. subspecies ''rubra'' (A.St.-Hil.)]]
[[Image:Oxalis corymbosa 2.jpg|thumb|right|''[[Oxalis debilis]]'' Kunth varietas ''[[corymbosa]]'' (DC.) Lourteig, 1981]]
[[Image:Oxalis dehradunensis (Dun Ambushi) in Hyderabad, AP W IMG 9725.jpg|thumb|''[[Oxalis dehradunensis]]'' Raizada, 1976]]
[[Image:Oxalis gigantea 1.jpg|thumb|right|''[[Oxalis gigantea]]'' Barneoud, 1846]]
[[Image:Oxalis luteola 1.jpg|thumb|right|''[[Oxalis luteola]]'']]
[[Image:Oxalis magnifica 2.jpg|thumb|right|''[[Oxalis magnifica]]'' R.Knuth, 1919]]
[[File:Oxalis-pes-caprae-36-Zachi-Evenor.jpg|thumb|right|''[[Oxalis pes-caprae]]'', L]]
[[File:Oxalis priceae.jpg|thumb|right|''[[Oxalis priceae]]'' [[John Kunkel Small|Small]]]]
[[Image:Oxalis purpurea (Habitus) 2.jpg|thumb|right|''[[Oxalis purpurea]]'' L., 1753]]
[[Image:Oxalis spiralis vulcanicola.jpg|thumb|right|''[[Oxalis spiralis]] vulcanicola'' Donn.Sm.]]
[[File:Oxalis tetraphylla leaves.jpg|thumb|right|''[[Oxalis tetraphylla]]'' ]]
* ''[[Oxalis acetosella]]'' &ndash; common wood sorrel, stabwort
* ''[[Oxalis adenophylla]]'' &ndash; Chilean oxalis, silver shamrock
* ''[[Oxalis albicans]]'' &ndash; hairy woodsorrel, white oxalis, radishroot woodsorrel, radishroot yellow-sorrel, California yellow-sorrel
* ''[[Oxalis alpina]]'' &ndash; alpine sorrel
* ''[[Oxalis ambigua]]''
* ''[[Oxalis articulata]]'' <small>Savign.</small> &ndash; pink-sorrel
* ''[[Oxalis ausensis]]''
* ''[[Oxalis barrelieri]]'' &ndash; lavender sorrel
* ''[[Oxalis bowiei]]'' &ndash; Bowie's wood-sorrel, Cape shamrock
* ''[[Oxalis brasiliensis]]'' &ndash; Brazilian woodsorrel
* ''[[Oxalis caerulea]]'' &ndash; blue woodsorrel
* ''[[Oxalis caprina]]''
* ''[[Oxalis corniculata]]'' &ndash; creeping wood sorrel, procumbent yellow-sorrel, sleeping beauty, ''chichoda bhaji'' (India)
* ''[[Oxalis debilis]]'' <small>Kunth</small>
* ''[[Oxalis decaphylla]]'' &ndash; ten-leaved pink-sorrel, tenleaf wood sorrel
* ''[[Oxalis dehradunensis]]''
* ''[[Oxalis depressa]]''
* ''[[Oxalis dichondrifolia]]'' &ndash; peonyleaf wood sorrel
* ''[[Oxalis dillenii]]'' <small>Jacquin</small> &ndash; southern yellow woodsorrel, Dillen's woodsorrel, Sussex yellow-sorrel
* ''[[Oxalis drummondii]]'' &ndash; Drummond's woodsorrel, chevron oxalis
* ''[[Oxalis ecuadorensis]]''
* ''[[Oxalis enneaphylla]]'' &ndash; scurvy-grass sorrel
* ''[[Oxalis exilis]]'' &ndash; least yellow-sorrel
* ''[[Oxalis frutescens]]'' &ndash; shrubby wood-sorrel
* ''[[Oxalis gigantea]]''
* ''[[Oxalis glabra]]'' – finger-leaf
* ''[[Oxalis grandis]]'' &ndash; great yellow-sorrel, large yellow woodsorrel
* ''[[Oxalis griffithii]]'' <small>Edgew. & Hook.f.</small>
* ''[[Oxalis hedysaroides]]'' &ndash; fire fern
* ''[[Oxalis hirta]]'' &ndash; hairy sorrel
* ''[[Oxalis illinoensis]]'' &ndash; Illinois wood-sorrel
* ''[[Oxalis inaequalis]]''
* ''[[Oxalis incarnata]]'' <small>L.</small> &ndash; pale pink-sorrel
* ''[[Oxalis lasiandra]]'' &ndash; Mexican shamrock
* ''[[Oxalis latifolia]]'' <small>Kunth</small> &ndash; garden pink-sorrel
* ''[[Oxalis luederitzii]]''
* ''[[Oxalis luteola]]'' <small>Jacq.</small>
* ''[[Oxalis magellanica]]'' <small>G.Forst.</small>
* ''[[Oxalis magnifica]]'' <small>Kunth</small> – snowdrop wood-sorrel
* ''[[Oxalis massoniana]]''
* ''[[Oxalis megalorrhiza]]'' &ndash; fleshy yellow-sorrel
* ''[[Oxalis melanosticta]]''
* ''[[Oxalis micrantha]]'' – dwarf woodsorrel
* ''[[Oxalis montana]]'' &ndash; mountain woodsorrel, white woodsorrel
* ''[[Oxalis nelsonii]]'' &ndash; Nelson's sorrel
* ''[[Oxalis norlindiana]]''
* ''[[Oxalis obliquifolia]]''
* ''[[Oxalis oregana]]'' &ndash; redwood sorrel, Oregon sorrel
* ''[[Oxalis ortgiesii]]'' <small>Regel</small> – fishtail oxalis
* ''[[Oxalis pennelliana]]''
* ''[[Oxalis pes-caprae]]'' &ndash; Bermuda-buttercup, African wood-sorrel, Bermuda sorrel, buttercup oxalis, Cape sorrel, English weed, soursob, "[[goat's-foot]]", "[[sourgrass]]", soursop (not to be confused with [[soursop|the fruit of that name]])
* ''[[Oxalis priceae]]'' &ndash; tufted yellow-sorrel
* ''[[Oxalis pulchella]]''
* ''[[Oxalis purpurea]]'' <small>L.</small> &ndash; purple wood-sorrel
* ''[[Oxalis rosea]]'' <small>Feuillée ex Jacq.</small> &ndash; annual pink-sorrel
* ''[[Oxalis rubra]]'' <small>A.St.-Hil.</small> &ndash; red wood-sorrel
* ''[[Oxalis rufescens]]''
* ''[[Oxalis rugeliana]]'' &ndash; coamo
* ''[[Oxalis rusciformis]]''
* ''[[Oxalis schaeferi]]''
* ''[[Oxalis spiralis]]'' &ndash; spiral sorrel, volcanic sorrel, velvet oxalis
* ''[[Oxalis stricta]]'' &ndash; common yellow woodsorrel, common yellow oxalis, upright yellow-sorrel, lemon clover, "[[pickle plant]]", "[[sourgrass]], "yellow woodsorrel"
* ''[[Oxalis suksdorfii]]'' &ndash; western yellow woodsorrel, western yellow oxalis
* ''[[Oxalis tenuifolia]]'' &ndash; thinleaf sorrel
* ''[[Oxalis tetraphylla]]'' &ndash; four-leaved pink-sorrel, four-leaf sorrel, [[Iron Cross]] oxalis, "[[lucky clover]]"
* ''[[Oxalis triangularis]]'' &ndash; threeleaf purple shamrock
* ''[[Oxalis trilliifolia]]'' &ndash; great oxalis, threeleaf woodsorrel
* ''[[Oxalis tuberosa]]'' &ndash; oca, oka, New Zealand yam
* ''[[Oxalis valdiviensis]]'' &ndash; Chilean yellow-sorrel
* ''[[Oxalis virginea]]'' &ndash; virgin wood-sorrel
* ''[[Oxalis versicolor]]'' – candycane sorrel 
* ''[[Oxalis violacea]]'' &ndash; violet wood-sorrel
* ''[[Oxalis vulcanicola]]'' &ndash; volcanic sorrel or velvet oxalis<ref>{{Cite web |url=https://plants.usda.gov/java/ClassificationServlet?source=profile&symbol=OXALI&display=31 |title=Classification &#124; USDA PLANTS |website=plants.usda.gov |access-date=2021-01-17 |archive-date=2021-01-17 |archive-url=https://web.archive.org/web/20210117034413/https://www.plants.usda.gov/java/ClassificationServlet?source=profile&symbol=OXALI&display=31 |url-status=live }}</ref><ref>{{Cite web |url=http://www.guynesom.com/CorniculataeSidoid09.pdf |title=Again: Taxonomy Of Yellow-Flowered Caulescent Oxalis (Oxalidaceae) In Eastern North America J. Bot. Res. Inst. Texas 3(2): 727 – 738. 2009 |access-date=2013-10-24 |archive-date=2013-10-29 |archive-url=https://web.archive.org/web/20131029185115/http://www.guynesom.com/CorniculataeSidoid09.pdf |url-status=live }}</ref>

==References==
{{Reflist|2}}

==Further reading==
<!-- These were probable used for the orig article but lets call it Further reading-->
* Bais, Harsh Pal; Vepachedu, Ramarao & Vivanco, Jorge M. (2003): Root specific elicitation and exudation of fluorescent β-carbolines in transformed root cultures of ''Oxalis tuberosa. Plant Physiology and Biochemistry'' '''41'''(4): 345–353. <small>{{doi|10.1016/S0981-9428(03)00029-9}}</small> [https://web.archive.org/web/20080905145156/http://lamar.colostate.edu/~jvivanco/papers/PPB/2003.pdf Preprint PDF fulltext]
* Łuczaj, Łukasz (2008): Archival data on wild food plants used in Poland in 1948. ''Journal of Ethnobiology and Ethnomedicine'' '''4''': 4<!-- BMC journal, uses article numbers not page numbers -->. <small>{{doi|10.1186/1746-4269-4-4}}</small> [http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=2275233&blobtype=pdf PDF fulltext]

{{Taxonbar|from=Q157378}}
{{Authority control}}

[[Category:Oxalis| ]]
[[Category:Oxalidales genera]]