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Dioscorea alata - L.

Common Name Water Yam, Purple yam, Greater yam, White yam
Family Dioscoreaceae
USDA hardiness 10-12
Known Hazards Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves[ 174 ]. The uncooked tuber of this species is toxic, and is said to produce narcosis[ 332 ]. Saponin is present and cooking renders the tubers safe to eat[ 332 ].
Habitats Not known in a wild state.
Range Probably arose in cultivation in E. Asia - Malaysia.
Edibility Rating    (4 of 5)
Other Uses    (2 of 5)
Weed Potential Yes
Medicinal Rating    (1 of 5)
Care (info)
Tender Moist Soil Semi-shade
Dioscorea alata Water Yam, Purple yam, Greater yam, White yam

Dioscorea alata Water Yam, Purple yam, Greater yam, White yam


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Water Yam or Dioscorea alata is a tuberous root vegetable originated in the Asian tropics. Its tubers are usually bright lavender in colour. It is also known as purple yam, greater yam, Guyana arrowroot, ten months yam, white yam, and winged yam. It is perennial, fast growing, and climbing plant that grows up to 15 m long. The tubers are cooked ? used in variety of desserts and as flavouring. It can be toxic if eaten raw. Medicinally, it is used as a laxative and verfimuge and used to treat fever, gonorrhoea, leprosy, tumours, and inflamed haemorrhoids.

Physical Characteristics

 icon of manicon of flower
Dioscorea alata is an evergreen Perennial Climber growing to 15 m (49ft) by 0.5 m (1ft 8in) at a fast rate.
See above for USDA hardiness. It is hardy to UK zone 10. The flowers are pollinated by Wind, Insects. The plant is not self-fertile.
Suitable for: light (sandy), medium (loamy) and heavy (clay) soils, prefers well-drained soil and can grow in nutritionally poor soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland). It prefers moist soil.

UK Hardiness Map US Hardiness Map


Dioscorea atropurpurea Roxb. Dioscorea globosa Roxb. Dioscorea javanica Queva. Dioscorea purpurea Ro


Edible Uses

Edible Parts: Root
Edible Uses: Colouring

Root - cooked[ 300 ]. Usually boiled or baked and used as a vegetable[ 300 , 301 ]. An average of 3 roots are produced by the plants, these usually each weigh in the range of 5 - 10kg, though exceptionally they can weigh up to 60 kg[ 300 ]. The root needs to be properly cooked, it can be toxic if eaten raw[ 332 ]. The plant produces aerial tubers and these can be eaten in the same way as the tubers[ 301 ].

References   More on Edible Uses

Medicinal Uses

Plants For A Future can not take any responsibility for any adverse effects from the use of plants. Always seek advice from a professional before using a plant medicinally.

The tuber is grated, mixed with brown stout vinegar, then spread onto paper and placed on the small of a woman's back to prevent or forestall a threatened miscarriage[ 348 ]. Although available as a dietary supplement and used in folk medicine, there is no clinical evidence that D. alata has any therapeutic properties. D. alata supplements may have adverse effects in people taking estrogens, anticoagulant drugs or during pregnancy and breast-feeding. D. alata has relatively high levels of oxalates (486–781 mg/100 g dry matter).

References   More on Medicinal Uses

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Other Uses

Dye  Fodder

Fodder/animal feed. Agroforestry. Ornamental. Medicinal: Traditional/folklore. Purple variety colour is due to various water-soluble anthocyanin pigments and is used as a food colouring agent.

Special Uses

Food Forest

References   More on Other Uses

Cultivation details

Plants grow best in lowland tropical areas up to an elevation of 1,000 metres with a temperature around 26 - 34°c; a well-defined dry season of 4 - 5 months; and a total rainfall of 1,000 - 1,500mm evenly distributed throughout the remainder of the year[ 300 ]. Plants are not frost tolerant[ 418 ]. Amongst the many cultivars of this species, there are forms that are tolerant of a wide range of environmental conditions[ 300 ]. For best yields, this species requires a deep, well-drained, sandy loam that is not liable to water-logging[ 300 ]. It also grows well in medium to clay loams[ 300 ]. Although more tolerant of poor soils than most other members of this genus, plants respond well to the application of organic matter[ 300 ]. Prefers a pH in the range 5.5 - 6.5, tolerating 4.8 - 8.5[ 418 ]. Daylengths of more than 12 hours are preferred during the early growing season since this encourages vegetative growth; daylengths of less than 12 hours towards the end of the growing season will encourage tuber formation and development[ 300 ]. Plants take 7 - 10 months to mature a crop[ 300 ]. Yields of 20 - 25 tonnes per hectare have been obtained[ 300 ]. There are some named varieties[ 300 , 301 ]. A dioecious species, both male and female plants need to be grown if seed is required.

References   Carbon Farming Information and Carbon Sequestration Information

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Seed - rarely produced in cultivation, they are not normally used to propagate this species. Cuttings of tubers. Small tubers can be cut into 2 - 4 sections, larger ones into 6 - 8 sections. Each section should have 2 - 3 dormant buds. The cut tuber is often left in the sun for several hours to promote wound healing and reduce the risk of fungal infection[ 300 ]. Aerial tubers can also be used, they usually produce vigorous plants[ 300 ].

Other Names

If available other names are mentioned here

geflügelter yam, grande igname, greater yam, guyana arrowroot, igname ailée, igname de chine, inhame, sewalli kodi, storjams, tabena, ten-months yam, wasser yamswurzel, water yam, white yam, winged yam, yam, ñame blanco, ñame de agua, Ambi, Asiatic yam, Avase, Ba-chhim, Batatilla, Boboyassi, Chupri alu, Cucam, Cucui-mo, Dago, Damloong chhiem moen, Dandaba, Daunini, Duok, Ep, Gbara-gue, Goradu, Huwi, Igname ailea, Ilumbelumbe, Kaavathu, Kachchilkilangu, Kachil, Kaile, Kamo, Kap, Katalu, Katula, Kep, Kham, Khamalu, Khanulu, Khoai-mo, Kinampai, Kiseba, Kwalo kau, Lengu, Lipeta, Luktu, Mach alu, Man-sao, Man, Manbuo, Mon, Nane, Nangate, Nruireu, Obbi, Oewi, Onthalaigasu, Oo-yama-imo, Oobi, Ovy, Pacala, Pahui, Pandalamu, Perumvalli kizhangu, Pindalu, Pokok ubi, Ractaguranialu, Raja-ala, Rambachim, Ratula, Sakourou, Shen shu, Taai-shue, Tarul, Telngot, Tung-genasu, Tus, Ubi tiyang,

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Found In

Countries where the plant has been found are listed here if the information is available

Africa, Anguilla, Asia, Australia, Barbados, Benin, Brazil, Burma, Cambodia, Cameroon, Caribbean, Central Africa, Central America, China, Colombia, Comoros, Congo DR, Cook Islands, Costa Rica, Côte d'Ivoire, Cuba, East Africa, East Timor, Ethiopia, Fiji, Gabon, Gambia, Ghana, Guiana, Guinea, Guinée, Guinea-Bissau, Guyana, Haiti, Hawaii, Honduras, India, Indochina, Indonesia, Ivory Coast, Jamaica, Japan, Laos, Madagascar, Malawi, Malaysia, Mali, Marianas, Mexico, Mozambique, Myanmar, Nauru, New Caledonia, New Zealand, Nigeria, North America, Northeastern India, Pacific, Palau, Papua New Guinea, PNG, Philippines, Polynesia, Puerto Rico, Samoa, SE Asia, Senegal, Sierra Leone, Solomon Islands, Southern Africa, South America, Sri Lanka, St Lucia,

Weed Potential

Right plant wrong place. We are currently updating this section. Please note that a plant may be invasive in one area but may not in your area so it’s worth checking.

Vigorous twining herbaceous vine invasive outside cultivated areas. It is included in the Global Compendium of Weeds (Randall, 2012), and is listed as a “noxious weed” in Florida and as an invasive species in Cuba, Costa Rica and several islands in the Pacific [1d].

Conservation Status

IUCN Red List of Threatened Plants Status : This taxon has not yet been assessed.

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Latin NameCommon NameHabitHeightHardinessGrowthSoilShadeMoistureEdibleMedicinalOther
Dioscorea batatasChinese YamPerennial3.0 4-11  LMHSNM553
Dioscorea bulbiferaAerial Yam, Air PotatoPerennial Climber10.0 9-12 FLMHSNM420
Dioscorea cayennensisYellow Yam, Yellow Guinea yamPerennial Climber10.0 10-12 FLMSNM400
Dioscorea deltoideaYamPerennial Climber3.0 -  LMHSNM222
Dioscorea esculentaLesser Yam, Potato Yam, Chinese Yam, Wild YamPerennial Climber3.0 8-12 FLMSNM400
Dioscorea japonicaGlutinous Yam, Japanese yamPerennial Climber3.0 7-12  LMHNM420
Dioscorea kamoonensis Perennial Climber2.5 -  LMHNM21 
Dioscorea tokoro Perennial Climber0.0 -  LMHNM22 
Dioscorea trifidaCush Cush Yam, Sweet yamPerennial Climber3.0 10-12 FLMHSNM402
Dioscorea villosaWild YamPerennial Climber3.0 5-9  LMHNM24 
Tamus communisBlack BryonyPerennial Climber3.5 4-8 MLMHSNM12 

Growth: S = slow M = medium F = fast. Soil: L = light (sandy) M = medium H = heavy (clay). pH: A = acid N = neutral B = basic (alkaline). Shade: F = full shade S = semi-shade N = no shade. Moisture: D = dry M = Moist We = wet Wa = water.


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A special thanks to Ken Fern for some of the information used on this page.

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