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Dioscorea wallichii was named by Joseph D. Hooker (1817-1911) in honour of Nathaniel Wallich (1786-1854), a surgeon and botanist who was involved in the development of the Botanic Garden, Calcutta. The tubers of D. wallichii are edible when boiled and peeled but are buried deep under the soil so they can be hard to extract.

Dioscorea wallichii (kruo)

[KSP]

Kew Species Profiles

General Description

Dioscorea wallichii was named by Joseph D. Hooker (1817-1911) in honour of Nathaniel Wallich (1786-1854), a surgeon and botanist who was involved in the development of the Botanic Garden, Calcutta. The tubers of D. wallichii are edible when boiled and peeled but are buried deep under the soil so they can be hard to extract.

Species Profile
Geography and distribution

Dioscorea wallichii is found in India, Bangladesh, Burma, Thailand and China. It climbs on large shrubs or trees in mixed deciduous forest and evergreen montane forest. It also occurs in disturbed areas along roadsides and edges of cultivated areas.

Description

Overview: A large, hairless climber that can grow to at least 20 m long. It has one edible, cylindrical tuber (or sometimes one that is used for growth whilst new one is forming) that can be over 1 m long and 3-6 cm wide. The tuber is white when young, becoming yellow and stringy with age.

Stem and leaves: The right-twining stem is woody and armed with spines at the base, herbaceous above and round in cross-section. Leaves are usually 8-19 x 8-21 cm and are more or less heart-shaped, with 5-7 main veins.

Flowers: Like almost all yams ( Dioscorea species), D. wallichii has separate male and female plants. The female inflorescences (flowering structures) hang down from the vine, each one containing up to 20 flowers. Male inflorescences are also pendent, and the male flowers are green and about 1 mm long.

Fruits: Round capsules contain flat, brown seeds, each with a thin, marginal wing.

Threats and conservation

Common and widespread within its natural range, Dioscorea wallichii is not considered to be threatened. It appears to be tolerant of some disturbance, judging from the areas where it is found, hence the species is listed as Least Concern.

As with all edible species, it is desirable to monitor sustainability of use on a local level.

Conservation assessments carried out at Kew

Dioscorea wallichii is being monitored as part of the IUCN Sampled Red List Index for Plants project, which aims to produce conservation assessments for a representative sample of the world's plant species.

This information will then be used to monitor trends in extinction risk and help focus conservation efforts where they are needed most.

Uses

Tubers of Dioscorea wallichii are consumed on a local scale as a source of carbohydrates. They are eaten by ethnic groups such as the Sakai tribe, who live in the Banthad Range in Peninsular Thailand. They are also eaten by tribes in Orissa, India, during the winter months.

In other areas of India, D. wallichii has been described more as a famine food used in times of food shortage because the tubers are hard to extract and less desirable than those of other Dioscorea species.

In India, juice extracted from the tubers is drunk to treat jaundice.

This species at Kew

Pressed and dried specimens of Dioscorea wallichii are held in Kew's Herbarium, where they are available to researchers from around the world by appointment. The details of some of these specimens can be seen online in Kew's Herbarium Catalogue.

Distribution
China, India, Myanmar, Thailand
Ecology
Mixed deciduous and evergreen forest.
Conservation
Least Concern (LC) according to IUCN Red List criteria.
Hazards

None known.

[KSP]
Use
Food.

Native to:

Assam, Bangladesh, China South-Central, East Himalaya, India, Malaya, Myanmar, Thailand

English
Kruo

Dioscorea wallichii Hook.f. appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Sep 1, 1990 Haines, H.H. [5118], India K000401026
Sep 1, 1990 McClelland [s.n.], Myanmar K000401022
Sep 1, 1990 Haines, H.H. [2463], India K000401024
Nov 28, 1989 Hansen, B. [12752], Thailand K000401055
Dec 1, 1983 Clarke, C.B. [20369], Jharkhand K000098208 lectotype
Dec 1, 1983 Gomez, W. [5708], Myanmar K000098209 paratype
Dec 1, 1983 Lace, J.H. [5469], Myanmar K000401035
Dec 1, 1983 Haines, H.H. [695], India K000401033
Wilkin, P. [933], Thailand K000401046
Wilkin, P. et al. [1026], Thailand K000401054
Haines, H.H. [496], India K000401032
Wilkin, P. [912], Thailand K000401041
Wilkin, P. [921], Thailand K000401044
Wilkin, P. [1050], Thailand K000401051
Meebold, A.K. [10900], India K000401034
Boyce, P.C. [808], Vietnam K000401057
s.coll [R 11067] K001142677
Haines, H.H. [2432], India K000401018
Keenan, R.L. [s.n.], India K000401027
Wilkin, P. [1050], Thailand K000401050
Wilkin, P et al. [1041], Thailand K000401049
Wilkin, P. [1072], Thailand K000401052
Boyce, P.C. [808], Vietnam K000401056
s.coll [s.n.] K000401020
Haines, H.H. [2452], India K000401017
Wilkin, P. [921], Thailand K000401045
Fernandes, J. [1007], India K001142678
Kerr, A.F.G. [16244], Thailand K000401040
Wilkin, P. [1078], Thailand K000401048
Wilkin, P. [1049], Thailand K000401053
Haines, H.H. [690], India K000401015
Haines, H.H. [693] K001142676
Hooker, J.D. [s.n.], Bangladesh K000401030
Haines, H.H. [693], India K000401014
Wilkin, P. [921], Thailand K000401043
s.coll [s.n.] K000401021
s.coll [1441], India K000401029
Clarke, C.B. [42291 A] K000401025
Wilkin, P. [1070], Thailand K000401047
Gamble, J.S. [[15375]], India K000401023
Wilkin, P. [912], Thailand K000401042
Fernandez, J. [1007], India K000401037
Keenan, R.L. [s.n.], India K000401031
Narayavaswami, V. [611], India K000401028
Haines, H.H. [CN 695 a], India K000401016

First published in Fl. Brit. India 6: 295 (1892)

Accepted by

  • Bhattacharya, R.P., Pal, D.C. & Pati, B.R. (2014). A sytematic census of monocot climbers of Bihar anf Jharkhand states Indian Journal of Forestry 37: 317-324.
  • Govaerts, R. (2000). World Checklist of Seed Plants Database in ACCESS D: 1-30141.
  • Govaerts, R., Wilkin, P. & Saunders, R.M.K. (2007). World Checklist of Dioscoreales. Yams and their allies: 1-65. The Board of Trustees of the Royal Botanic Gardens, Kew.
  • Wilkin, P. & Thapyai, C. (2009). Flora of Thailand 10(1): 1-140. The Forest Herbarium, National Park, Wildlife and Plant Conservation Department, Bangkok.
  • Wilkin, P., Thapyai, C. & Chayamarit, K. (2007). Lectotypification of Dioscorea L. (Dioscoreaceae) names from Thailand Kew Bulletin 62: 251-258.

Literature

Kew Species Profiles

  • Contu, S. (2009). Dioscorea wallichii. In: IUCN Red List of Threatened Species, Version 2011.2. < www.iucnredlist.org> (accessed 11 March 2012).
  • Edison, S. et al. (2006). Biodiversity of Tropical Tuber Crops in India. National Biodiversity Authority, Chennai, Tamil Nadu, India.
  • Maneenoon, K., Sirirugsa, P. & Sridith, K. (2008). Ethnobotany of Dioscorea L. (Dioscoreaceae), a major food plant of the Sakai Tribe at Banthad Range, Peninsular Thailand. Ethnobotany Research and Applications 6: 385–394.
  • Prain, D. & Burkill, I. H. (1938). An account of the genus Dioscorea in the East, Part 2: The species which twine to the right. Annals of the Royal Botanic Gardens, Calcutta 14: 211–528.
  • Sinha, R. & Lakra, V. (2005). Wild tribal food plants of Orissa. Indian Journal of Traditional Knowledge 4: 246–252.
  • Ting, C. & Gilbert, M. G. (2000). Dioscoreaceae. In: Flora of China.
  • Wilkin, P. & Thapyai, C. (2009). Dioscoreaceae. In: Flora of Thailand, ed. T. Santsuk & K. Larsen, pp. 1–140, The Forest Herbarium, Bangkok.
  • World Checklist of Selected Plant Families (2010). Dioscorea wallichii. The Board of Trustees of the Royal Botanic Gardens, Kew.

Herbarium Catalogue Specimens
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Species Profiles
Kew Species Profiles
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