Editing Dioscorea alata

{{Short description|Species of yam}}
{{redirect|Water yam|the book|Water Yam (artist's book)}}
{{Use American English|date=April 2024}}
{{Use mdy dates|date=April 2024}}
{{cs1 config|name-list-style=vanc|display-authors=3}}
{{Speciesbox
| image = Kambar wh.jpg
| image_caption = Cross section of purple yam
| image2 = 
| image2_alt = 
| image2_caption = 
| genus = Dioscorea
| species = alata
| authority = [[Carl Linnaeus|L.]]<ref name=trop>&nbsp;''Dioscorea alata'' was first described and published in ''[[Species Plantarum]]'' 2: 1033. 1753. {{ cite web |url=http://tropicos.org/Name/11000003 |title=Name – ''Dioscorea alata'' L. |work=Tropicos |publisher=[[Missouri Botanical Garden]] |location=[[Saint Louis, Missouri]] |access-date=May 26, 2011}}</ref>
| synonyms = {{collapsible list |
    {{plainlist | style = margin-left: 1em; text-indent: -1em; |
* ''Dioscorea atropurpurea'' <small>Roxb.</small>
* ''Dioscorea colocasiifolia''<small> Pax</small>
* ''Dioscorea eburina''<small> Lour.</small>
* ''Dioscorea eburnea''<small> Lour.</small>
* ''Dioscorea globosa''<small> Roxb.</small>
* ''Dioscorea javanica''<small> Queva</small>
* ''Dioscorea purpurea''<small> Roxb.</small>
* ''Dioscorea rubella''<small> Roxb.</small>
* ''Dioscorea sapinii''<small> De Wild.</small>
* ''Dioscorea sativa''<small> Munro</small>
* ''Dioscorea vulgaris''<small> Miq.</small>
* ''Elephantodon eburnea'' <small>(Lour.) Salisb.</small>
* ''Polynome alata'' <small>(L.) Salisb.</small>
    }}
  }}
| synonyms_ref = <ref>{{cite web |url=https://theplantlist.org/tpl/record/kew-239747 |title=The Plant List: A Working List of All Plant Species |access-date=November 4, 2023 |archive-date=May 13, 2024 |archive-url=https://web.archive.org/web/20240513153144/http://www.theplantlist.org/tpl/record/kew-239747 |url-status=dead }}</ref>
}}

'''''Dioscorea alata'''''{{snd}}also called '''ube''' ({{IPAc-en|'|uː|b|ɛ|,_|-|b|eɪ}}), '''ubi''', '''purple yam''', or '''greater yam''', among many other names{{snd}}is a species of [[Yam (vegetable)|yam]] (a [[tuber]]). The tubers are usually a vivid [[Violet (color)|violet]]-[[purple]] to bright [[Lavender (color)|lavender]] in color (hence the common name), but some range in color from cream to plain white. It is sometimes confused with [[taro]] and the Okinawa sweet potato {{nihongo|''beniimo''|紅芋}} (''Ipomoea batatas'' cv. [[List of sweet potato cultivars|Ayamurasaki]]), however ''D. alata'' is also grown in Okinawa. With its origins in the Asian and Oceanian [[tropics]], ''D. alata'' has been known to humans since ancient times.<ref name=grin>{{GRIN | access-date=May 26, 2011}}</ref>

==Names==
Because it has become naturalized following its origins in Asia, specifically the [[Philippines]], through tropical South America, and the southeastern U.S., ''D. alata'' is referred to by many different names in these regions. In English alone, aside from purple yam, other common names include '''ten-months yam''', '''water yam''', '''white yam''', '''winged yam''', '''violet yam''', '''Guyana arrowroot''', or simply '''yam'''.<ref name=grin/> 
{{missing information|wild relatives (D. nummularia, D. transverse, and D. hastifolia; progenitor unknown) [doi:10.1111/boj.12374])|date=October 2021}}

==History of cultivation==
[[File:Ubejf1680.JPG|thumb|Harvested purple yam tubers]]
''Dioscorea alata'' is one of the most important staple crops in [[Austronesian people|Austronesian cultures]]. It is one of various species of yams that were domesticated and cultivated independently within [[Island Southeast Asia]] and [[New Guinea]] for their starchy [[tuber]]s, including the round yam (''[[Dioscorea bulbifera]]''), ''ubi gadung'' (''[[Dioscorea hispida]]''), lesser yam (''[[Dioscorea esculenta]]''), Pacific yam (''Dioscorea nummularia''), fiveleaf yam (''[[Dioscorea pentaphylla]]''), and pencil yam (''[[Dioscorea transversa]]'').<ref name="Barker2017">{{cite journal |last1=Barker |first1=Graeme |last2=Hunt |first2=Chris |last3=Barton |first3=Huw |last4=Gosden |first4=Chris |last5=Jones |first5=Sam |last6=Lloyd-Smith |first6=Lindsay |last7=Farr |first7=Lucy |last8=Nyirí |first8=Borbala |last9=O'Donnell |first9=Shawn |title=The 'cultured rainforests' of Borneo |journal=Quaternary International |date=August 2017 |volume=448 |pages=44–61 |doi=10.1016/j.quaint.2016.08.018 |url=http://researchonline.ljmu.ac.uk/4693/3/The%20cultured%20rainforests%20of%20Borneo.pdf |bibcode=2017QuInt.448...44B}}</ref> Among these, ''D. alata'' and ''D. esculenta'' were the only ones regularly cultivated and eaten, while the rest were usually considered as [[famine food]] due to their higher levels of the toxin [[dioscorine]] which requires that they be prepared correctly before consumption.<ref name="Bevacqua1994">{{cite journal |last1=Bevacqua |first1=Robert F. |title=Origin of Horticulture in Southeast Asia and the Dispersal of Domesticated Plants to the Pacific Islands by Polynesian Voyagers: The Hawaiian Islands Case Study |journal=HortScience |date=1994 |volume=29 |issue=11 |pages=1226–1229 |url=http://hortsci.ashspublications.org/content/29/11/1226.full.pdf |doi=10.21273/HORTSCI.29.11.1226 |doi-access=free}}</ref> ''D. alata'' is also cultivated more than ''D. esculenta'', largely because of its much larger tubers.<ref name="temarareoUbe">{{cite web |url=http://www.temarareo.org/PPN-Qubi.html |title=*Qufi ~ Uwhi, uhi |work=Te Mära Reo: The Language Garden |publisher=Benton Family Trust|access-date=21 January 2019}}</ref>

''D. alata'' and ''D. esculenta'' were the most suitable for long transport in Austronesian ships and were carried through all or most of the range of the [[Austronesian expansion]]. ''D. alata'' in particular were introduced into the [[Pacific Islands]] and [[New Zealand]]. They were also carried by [[Austronesian peoples|Austronesian voyagers]] into [[Madagascar]] and the [[Comoros]].<ref name="Crowther2016">{{cite journal |last1=Crowther |first1=Alison |last2=Lucas |first2=Leilani |last3=Helm |first3=Richard |last4=Horton |first4=Mark |last5=Shipton |first5=Ceri |last6=Wright |first6=Henry T. |last7=Walshaw |first7=Sarah |last8=Pawlowicz |first8=Matthew |last9=Radimilahy |first9=Chantal |last10=Douka |first10=Katerina |last11=Picornell-Gelabert |first11=Llorenç |last12=Fuller |first12=Dorian Q. |last13=Boivin |first13=Nicole L. |title=Ancient crops provide first archaeological signature of the westward Austronesian expansion |journal=Proceedings of the National Academy of Sciences |date=14 June 2016 |volume=113 |issue=24 |pages=6635–6640 |doi=10.1073/pnas.1522714113 |pmid=27247383 |pmc=4914162|bibcode=2016PNAS..113.6635C |doi-access=free }}</ref><ref name="Beaujard2011">{{cite journal |last1=Beaujard |first1=Philippe |title=The first migrants to Madagascar and their introduction of plants: linguistic and ethnological evidence |journal=Azania: Archaeological Research in Africa |date=August 2011 |volume=46 |issue=2 |pages=169–189 |doi=10.1080/0067270X.2011.580142 |s2cid=55763047 |url=https://halshs.archives-ouvertes.fr/halshs-00706173/file/Beaujard.azania2.pdf}}</ref><ref name="WalterLebot2007">{{cite book |last1=Walter |first1=Annie |last2=Lebot |first2=Vincent |title=Gardens of Oceania |date=2007 |publisher=IRD Éditions-CIRAD |isbn=9781863204705 |url=https://books.google.com/books?id=SMYkLkV4iyEC}}</ref>
[[File:Starr 061106-9589 Dioscorea alata.jpg|thumb|Aerial bulbil of a white variety of ''D.&nbsp;alata'']]
The center of origin of purple yam is in [[Philippines|the Philippines]], but archaeological evidence suggests that it was exploited in [[Island Southeast Asia]] and [[New Guinea]] before the [[Austronesian expansion]]. Purple yam is believed to be a true [[cultigen]], only known from its cultivated forms. The vast majority of cultivars are sterile, which restricts its introduction into islands purely by human agency, making them a good indicator of human movement. Some authors have proposed, without evidence, an origin in [[Mainland Southeast Asia]], but it shows the greatest phenotypic variability in the [[Philippines]] and [[New Guinea]].<ref name="Malapa2005">{{cite journal |last1=Malapa |first1=R. |last2=Arnau |first2=G. |last3=Noyer |first3=J.L. |last4=Lebot |first4=V. |title=Genetic Diversity of the Greater Yam (Dioscorea alata L.) and Relatedness to D. nummularia Lam. and D. transversa Br. as Revealed with AFLP Markers |journal=Genetic Resources and Crop Evolution |date=November 2005 |volume=52 |issue=7 |pages=919–929 |doi=10.1007/s10722-003-6122-5|bibcode=2005GRCEv..52..919M |s2cid=35381460 }}</ref><ref name="Cruz1999">{{cite journal |last1=Cruz |first1=V.M.V. |last2=Altoveros |first2=N.C. |last3=Mendioro |first3=M.S. |last4=Ramirez |first4=D.A. |title=Geographical patterns of diversity in the Philippine edible yam collection |journal=Plant Genetic Resources Newsletter |date=1999 |volume=119 |pages=7–11}}</ref><ref name="Paz1999">{{cite journal |last1=Paz |first1=Victor J. |title=Neolithic Human Movement to Island Southeast Asia: The Search for Archaeobotanical Evidence |journal=Indo-Pacific Prehistory Association Bulletin |date=1999 |volume=18 |issue=Melaka Papers Vol. 2 |pages=151–158 |doi=10.7152/bippa.v18i0.11710 |doi-broken-date=November 1, 2024 |url=https://journals.lib.washington.edu/index.php/BIPPA/article/viewFile/11710/10339}}</ref>

Based on archaeological evidence of early farming plots and plant remains in the [[Kuk Swamp]] site, authors have suggested that it was first domesticated in the highlands of New Guinea from around 10,000 [[Before Present|BP]] and spread into Island Southeast Asia via the [[Lapita culture]] at around c. 4,000 [[Before Present|BP]], along with ''D. nummularia'' and ''D. bulbifera''. In turn, ''D. esculenta'' is believed to have been introduced by the Lapita culture into New Guinea. There is also evidence of an agricultural revolution during this period brought by innovations from contact with Austronesians, including the development of [[Paddy field|wet cultivation]].<ref name="Chaïr2016">{{cite journal |last1=Chaïr |first1=H. |last2=Traore |first2=R. E. |last3=Duval |first3=M. F. |last4=Rivallan |first4=R. |last5=Mukherjee |first5=A. |last6=Aboagye |first6=L. M. |last7=Van Rensburg |first7=W. J. |last8=Andrianavalona |first8=V. |last9=Pinheiro de Carvalho |first9=M. A. A. |last10=Saborio |first10=F. |last11=Sri Prana |first11=M. |last12=Komolong |first12=B. |last13=Lawac |first13=F. |last14=Lebot |first14=V. |last15=Chiang |first15=Tzen-Yuh |title=Genetic Diversification and Dispersal of Taro (''Colocasia esculenta'' (L.) Schott) |journal=PLOS ONE |date=17 June 2016 |volume=11 |issue=6 |pages=e0157712 |doi=10.1371/journal.pone.0157712 |pmid=27314588 |pmc=4912093 |bibcode=2016PLoSO..1157712C|doi-access=free }}</ref><ref name="Bayliss-Smith2017">{{cite book |first1=Tim |last1=Bayliss-Smith |first2=Jack |last2=Golson |first3=Philip |last3=Hughes|editor1-first=Jack |editor1-last=Golson |editor2-first=Tim |editor2-last=Denham|editor3-first=Philip |editor3-last=Hughes|editor4-first=Pamela|editor4-last= Swadling|editor5-first=John |editor5-last=Muke |title=Ten Thousand Years of Cultivation at Kuk Swamp in the Highlands of Papua New Guinea |chapter=Phase 4: Major Disposal Channels, Slot-Like Ditches and Grid-Patterned Fields |publisher=ANU Press |series=terra australis |volume=46 |year=2017 |pages=239–268 |isbn=9781760461164|chapter-url =https://books.google.com/books?id=Hlk0DwAAQBAJ&pg=PA239}}</ref> 

However, much older remains identified as being probably ''D. alata'' have also been recovered from the [[Niah Caves]] of [[Borneo]]  ([[Late Pleistocene]], <40,000 [[Before Present|BP]]) and the [[Ille Cave]] of [[Palawan]] (c. 11,000 [[Before Present|BP]]), along with remains of the toxic ''ubi gadung'' (''D. hispida'') which requires processing before it can be edible. Although it doesn't prove cultivation, it does show that humans already had the knowledge to exploit starchy plants and that ''D. alata'' were native to Island Southeast Asia. Furthermore, it opens the question on whether ''D. alata'' is a true species or cultivated much older than believed.<ref name="Barker2017"/><ref name="Barker2011">{{cite journal |last1=Barker |first1=Graeme |last2=Lloyd-Smith |first2=Lindsay |last3=Barton |first3=Huw |last4=Cole |first4=Franca |last5=Hunt |first5=Chris |last6=Piper |first6=Philip J. |last7=Rabett |first7=Ryan |last8=Paz |first8=Victor |last9=Szabó |first9=Katherine |title=Foraging-farming transitions at the Niah Caves, Sarawak, Borneo |journal=Antiquity |date=2011 |volume=85 |issue=328 |pages=492–509 |doi=10.1017/S0003598X00067909 |s2cid=131187696 |doi-access=free}}</ref><ref name="Balbaligo2007">{{cite journal |last1=Balbaligo |first1=Yvette |title=A Brief Note on the 2007 Excavation at Ille Cave, Palawan, the Philippines |journal=Papers from the Institute of Archaeology |date=15 November 2007 |volume=18 |issue=2007 |pages=161 |doi=10.5334/pia.308 |doi-access=free}}</ref><ref name="Barton2005">{{cite journal |last1=Barton |first1=Huw |title=The Case for Rainforest Foragers: The Starch Record at Niah Cave, Sarawak |journal=Asian Perspectives |date=2005 |volume=44 |issue=1 |pages=56–72 |url=https://core.ac.uk/download/pdf/5105493.pdf |doi=10.1353/asi.2005.0005 |hdl=10125/17222 |s2cid=11596542 |hdl-access=free}}</ref><ref name="HuwDenham2011">{{cite book |first1=Huw |last1=Barton |first2=Timothy |last2=Denham |editor1-first=Grame |editor1-last=Barker |editor2-first=Monica |editor2-last=Janowski |title=Why cultivate? Anthropological and Archaeological Approaches to Foraging–Farming Transitions in Southeast Asia |chapter=Prehistoric vegeculture and social life in Island Southeast Asia and Melanesia |publisher=McDonald Institute for Archaeological Research |year=2011 |pages=61–74 |isbn=9781902937588 |chapter-url=http://austronesian.linguistics.anu.edu.au/historydownloads/Barton_Denham_2011.pdf |access-date=2019-01-21 |archive-date=2019-03-28 |archive-url=https://web.archive.org/web/20190328172327/http://austronesian.linguistics.anu.edu.au/historydownloads/Barton_Denham_2011.pdf |url-status=dead }}</ref><ref name="Reynolds2013">{{cite book |first1=Tim |last1=Reynolds |first2=Graeme |last2=Barker |first3=Huw |last3=Barton |first4=Gathorne |last4=Cranbrook |first5=Chris |last5=Hunt |first6=Lisa |last6=Kealhofer |first7=Victor |last7=Paz |first8=Alasdair |last8=Pike |first9=Philip |last9=Piper|first10=Ryan |last10=Rabett |first11=Gary |last11=Rushworth |first12=Christopher |last12=Stimpson |first13=Katherine |last13=Szabó|editor1-first=Graeme|editor1-last=Barker |title=Rainforest Foraging and Farming in Island Southeast Asia |chapter=The First Modern Humans at Niah, c. 50,000–35,000 Years Ago |publisher=McDonald Institute for Archaeological Research |year=2013 |pages=133–170 |isbn=9781902937540|chapter-url =https://pages.upd.edu.ph/sites/default/files/pawlik/files/niah_ch04_the_first_modern_humans_at_niah.pdf}}</ref>

Purple yam remains an important crop in Southeast Asia, particularly in the [[Philippines]] where the vividly purple variety is widely used in various traditional and modern desserts. It also remains important in [[Melanesia]], where it is also grown for ceremonial purposes tied to the size of the tubers at harvest time. Its importance in eastern [[Polynesia]] and [[New Zealand]], however, has waned after the introduction of other crops, most notably the [[sweet potato]].<ref name="temarareoUbe"/>

==Uses==
===Culinary===
Purple yams have edible tubers which have a mildly sweet, earthy and nutty taste, reminiscent of [[sweet potato]]es or [[taro]]. The violet cultivars, in particular, turn dishes distinctively vivid violet because of the high amount of [[anthocyanin]]s.<ref name="Chowhound">{{cite web |last1=Sutherlin |first1=Margaret |title=Everything You Need to Know About Ube, The Purple Yam |url=https://www.chowhound.com/food-news/189640/everything-you-need-to-know-about-ube-the-purple-yam/ |website=Chowhound |access-date=18 May 2019}}</ref> Purple yams are also valued for the [[starch]] that can be processed from them.<ref name=grin/> 
Purple yam is most common in [[Philippine cuisine]] (where it is known as ''ube'' or ''ubi''). It is widely applied for many Philippine desserts, such as [[ube cake]], [[ube cheesecake]] and [[ube crinkles]], as well as an ingredient or flavor for [[ice cream]], [[Flavored milk|milk]], [[donut]]s, [[tart]]s, jam and other types of [[pastries]]. It is often eaten boiled, baked, or as a sweetened dessert called ''[[Ube halaya|ube halayá]]''; the latter being a popular ingredient in the iced dessert called ''[[halo-halo]]''.<ref name="Kearns">{{cite news |last1=Kearns |first1=Landess |title=Ube Is The Natural Ingredient That Turns Food Perfectly Purple |url=https://www.huffpost.com/entry/ube-purple-yam_n_57e19ec0e4b0e28b2b50c17f |access-date=18 May 2019 |work=The Huffington Post}}</ref><ref>{{cite web |last1=Bueno |first1=Anna |title=All hail ube, the culinary gem we took for granted |url=http://nine.cnnphilippines.com/life/leisure/food/2016/10/14/ube-cover-story.html |website=CNN Philippines |access-date=18 May 2019 |archive-date=1 November 2019 |archive-url=https://web.archive.org/web/20191101191518/http://nine.cnnphilippines.com/life/leisure/food/2016/10/14/ube-cover-story.html |url-status=dead }}</ref><ref>{{cite web |last1=Valdeavilla |first1=Ronica |title=Ube: The Philippine Purple Yam (More Popular Than Vanilla!) |url=https://theculturetrip.com/asia/philippines/articles/ube-the-philippine-purple-yam-more-popular-than-vanilla/ |website=culture trip |date=6 June 2018 |access-date=18 May 2019}}</ref> Purple yam desserts have more recently entered the [[United States]] through Philippine cuisine, under the Filipino name "ube". It is particularly popular due to the striking violet-purple color it gives to desserts.<ref name="Chowhound"/><ref name="Kearns"/><ref>{{cite web |url=http://abc7chicago.com/food/donut-shop-in-gurnee-cranks-out-unique-freshly-made-donuts/1602514/ |title=Donut Shop in Gurnee Cranks Out Unique Freshly Made Donuts |date=November 11, 2016 |publisher=ABC7 Chicago}}</ref>

Purple yam is commonly confused with purple/violet varieties of [[sweet potato]]es because of their similarities in color, taste, and culinary uses. However, like other yams, purple yam tends to have a moister texture than sweet potatoes. Purple yams also have higher anthocyanin content than sweet potatoes. They can otherwise be used interchangeably in most recipes.<ref>{{cite web |title=Ube or Not Ube, That Is the Question…and Frieda's Is Answering |url=https://www.friedas.com/ube-or-not-ube-that-is-the-questionand-friedas-is-answering/ |website=Frieda's |date=17 April 2017 |access-date=18 May 2019}}</ref><ref>{{cite web |title=Ingredient Spotlight: Ube, the Purple Yams That Make Dessert |url=https://www.onegreenplanet.org/vegan-food/ingredient-spotlight-ube/ |website=OneGreenPlanet |access-date=18 May 2019 |date=2017-03-24}}</ref>

<gallery>
Ube halaya, Filipino dessert.jpg|[[Ube halaya]] (mashed purple yam) from the Philippines
Ube champorado.jpg|Ube [[champorado]] from the Philippines
Piaya flatbread (Philippines) 01.jpg|Ube and [[muscovado]] piayas from the Philippines
Undhiyu.jpg|[[Undhiyu]] from [[Gujarat]], [[India]]
Okinawan sweet potato pancakes with coconut ube sauce.jpg|[[Okinawan cuisine|Okinawan]] sweet potato pancakes with coconut ube sauce
Ube crepe cake.jpg|A slice of ube [[Mille crepe cake|crepe cake]]
Ubecupcakes.jpg|Purple yam cupcakes with flan top layers
Ube doughnut.jpg|[[Philippines|Filipino]] ube donut
File:Ube_Mamón1.jpg |Ube [[Mamón]]
Halo-Halo.jpg|[[Halo-halo]] with [[ube halaya]]
</gallery>

===Supplements, folk medicine and adverse effects===
Although available as a [[dietary supplement]] and used in [[traditional medicine|folk medicine]], there is no [[evidence-based medicine|clinical evidence]] that ''D. alata'' has any therapeutic properties.<ref name="drugs">{{cite web |title=Wild yam |url=https://www.drugs.com/mtm/wild-yam.html |publisher=Drugs.com |access-date=15 March 2021 |date=24 July 2020}}</ref> Use of ''D. alata'' supplements may have [[adverse effect]]s in people taking [[estrogen]]s, [[anticoagulant]] drugs or during pregnancy and breast-feeding.<ref name=drugs/> Some people may have [[allergic reaction]]s to use of ''D. alata'' supplements.<ref name=drugs/>

''D. alata'' has relatively high levels of [[oxalate]]s (486–781&nbsp;mg/100 g dry matter),<ref name="pmid7971785">{{cite journal |vauthors=Wanasundera JP, Ravindran G |s2cid=36080604 |title=Nutritional assessment of yam (''Dioscorea alata'') tubers |journal=Plant Foods Hum Nutr |volume=46 |issue=1 |pages=33–9 |year=1994 |pmid=7971785 |doi=10.1007/BF01088459|bibcode=1994PFHN...46...33W }}</ref> which are associated with [[antinutrient|antinutritional effects]] and [[Oxalate#Physiological_effects|kidney stone]] formation.<ref name="otegbayo">{{cite journal |last1=Otegbayo |first1=B. O. |last2=Oguniyan |first2=D. J. |last3=Olunlade |first3=B. A. |last4=Oroniran |first4=O. O. |last5=Atobatele |first5=O. E. |title=Characterizing genotypic variation in biochemical composition, anti-nutritional and mineral bioavailability of some Nigerian yam (Dioscorea spp.) land races |journal=Journal of Food Science and Technology |volume=55 |issue=1 |date=2017-11-01 |issn=0022-1155 |pmid=29358812 |pmc=5756202 |doi=10.1007/s13197-017-2913-0 |pages=205–216}}</ref>

===Other uses===
The color of purple varieties is due to various [[anthocyanin]] pigments.<ref name="mori">{{cite journal |vauthors=Moriya C, Hosoya T, Agawa S, Sugiyama Y, Kozone I, Shin-Ya K |title=New acylated anthocyanins from purple yam and their antioxidant activity. |journal=Biosci Biotechnol Biochem |year=2015 |volume=79 |issue=9 |pages=1484–92 |pmid=25848974 |doi=10.1080/09168451.2015.1027652 |s2cid=11221328 |doi-access=free }}</ref> The pigments are water-soluble, and have been proposed as possible [[food coloring]] agents.<ref name="LiZhang">{{cite journal |last1=Li |first1=Jinwei |last2=Zhang |first2=Lianfu |last3=Liu |first3=Yuanfa |year=2013 |title=Optimization of Extraction of Natural Pigment from Purple Sweet Potato by Response Surface Methodology and Its Stability |journal=Journal of Chemistry |volume=2013 |pages=1–5 |doi=10.1155/2013/590512 | doi-access = free}}</ref> ''D. alata'' is sometimes grown in gardens for its ornamental value.<ref name=grin/>

==As an invasive species==
''Dioscorea alata'' is native to the Philippines, as well as surrounding areas ([[Taiwan]] and the [[Ryukyu Islands]] of [[Japan]]).  It has escaped from its native growth area and into the wild in many other places, becoming [[Naturalisation (biology)|naturalized]] in parts of southern and east-central [[China]], [[Africa]] and [[Madagascar]], the [[Western Hemisphere]], and various islands in the [[Indian Ocean|Indian]] and [[Pacific Islands|Pacific]] oceans.<ref>[http://apps.kew.org/wcsp/namedetail.do?name_id=239747 Kew World Checklist of Selected Plant Families]</ref><ref>[http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200028084 Flora of China, Vol. 24 Page 296, shen shu, ''Dioscorea alata'' Linnaeus, Sp. Pl. 2: 1033. 1753. ]</ref> It persists in the wild in Haiti, as well as the [[United States]], in [[Hawaii]], [[Louisiana]], [[Georgia (U.S. state)|Georgia]], [[Alabama]], [[Puerto Rico]], the [[U.S. Virgin Islands]], and in [[Florida]] where it is considered an [[invasive species]].<ref name=plants>{{ cite web |url=http://plants.usda.gov/java/profile?symbol=DIAL2 |title=Profile for ''Dioscorea alata'' (water yam) |work=PLANTS Database |publisher=[[United States Department of Agriculture|USDA]], [[Natural Resources Conservation Service|NRCS]] |access-date=May 26, 2011}}</ref><ref>[http://bonap.net/MapGallery/County/Dioscorea%20alata.png Biota of North America Program, 2013 county distribution map]</ref>

==Gallery==
<gallery>
File:Starr 061106-1435 Dioscorea alata.jpg|Purple yam leaves
File:Starr-061106-1437-Dioscorea alata-flowers-Maui Nui Botanical Garden-Maui (24572888200).jpg|Purple yam flowers
</gallery>

==See also==
*[[Domesticated plants and animals of Austronesia]]
*''[[Colocasia esculenta]]''
*''[[Alocasia macrorrhizos]]''
*''[[Amorphophallus paeoniifolius]]''
*''[[Cyrtosperma merkusii]]''
*''[[Ipomoea batatas]]''

==References==
{{Reflist}}

==External links==
{{Commons category|Dioscorea alata|''Dioscorea&nbsp;alata''}}
{{Wikispecies|Dioscorea alata|''Dioscorea&nbsp;alata''}}
*{{ITIS |id=43372 |taxon=Dioscorea alata |access-date=18 February 2006}}
*[http://www.forestryimages.org/browse/subimages.cfm?sub=5535&search=Search Images] {{Webarchive|url=https://web.archive.org/web/20120320071314/http://www.forestryimages.org/browse/subimages.cfm?sub=5535&search=Search |date=March 20, 2012 }} from Forestry Images (webpages from the [[University of Georgia]]'s Center for Invasive Species and Ecosystem Health)

{{Taxonbar|from=Q1932852}}

[[Category:Dioscorea|alata]]
[[Category:Plants described in 1753]]
[[Category:Taxa named by Carl Linnaeus]]
[[Category:Yams (vegetable)]]
[[Category:Flora of tropical Asia]]
[[Category:Maharashtrian cuisine]]
[[Category:Filipino cuisine]]
[[Category:Austronesian agriculture]]