HOME

TheInfoList



OR:

''Dioscorea dumetorum'', also known as the bitter yam, cluster yam, trifoliate yam, or three-leaved yam, is a species of flowering plant in the yam family, '' Dioscorea.'' It is native to sub-saharan Africa and especially common in the tropical regions of West Africa, including Nigeria, Benin, and Ghana. ''D. dumetorum'' has both toxic and non-toxic varieties.


Description

''D. dumetorum'' has distinctive trifoliate leaves, similar to the Indian three-leaf yam ''
Dioscorea hispida ''Dioscorea hispida'', also known as the Indian three-leaved yam, (Tagalog: nami) is a species of yam in the genus ''Dioscorea'', native to South and Southeast Asia. Known to be poisonous when fresh, careful processing is required to render it e ...
''. Each leaf has 3 to 7 veins per leaflet. The vine has ridged ascending prickles and a characteristic twining to the left. ''D. dumetorum'' grows up onto shrubs and reaches heights of about 7 meters. The vines grow annually from the underground tubers. The tubers of ''D. dumetorum'' are deeply lobed and occur in clusters just below the surface of the soil. The flower of the bitter yam is brown. Male flowers are arranged in complex branched structures while female flowers are arranged in spikes. The seeds are winged capsules that are oblong in shape. Its wild form is highly toxic due to the high content of the alkaloids dihydrodioscorine and dioscorine. However, there are non-toxic edible cultivars in West Africa. For example, within Benin there are 15 identified non-toxic local varieties of ''D. dumetorum''.


Habitat

''D. dumetorum'' grows in disturbed areas such as riverbanks, forest margins, termite mounds, and rocky areas. Its range is throughout sub-saharan Africa. ''D. dumetorum'' is mainly cultivated in the
Bight of Biafra The Bight of Biafra (known as the Bight of Bonny in Nigeria) is a bight off the West African coast, in the easternmost part of the Gulf of Guinea. Geography The Bight of Biafra, or Mafra (named after the town Mafra in southern Portugal), between ...
region from southeast Nigeria to Gabon, as well in the Ubangi-Shari region of inland Central Africa.


Uses

''D. dumetorum'' is a famine food in West Africa. It is frequently planted as a backup harvest in cases of crop failure. However, the regular use of ''D. dumetorum'' is limited due to its frequent toxicity and tendency to harden after harvesting. Because of the toxicity of most trifoliate yam races, specific processing before consumption is required. Methods for detoxification include: placing in running water for 3-5 days or burying in black soil. Salt, Tamarind pods, or desert dates are sometimes added to these methods as detoxicants. In Mozambique, the tubers are first cut into thin slices, dried on rocks, and then undergo a detoxification process. Nontoxic varieties of ''D. dumetorum'' are common in West Africa. In countries such as Benin and Nigeria these varieties are farmed in subsistence agriculture. In West Africa, the non-toxic varieties of ''D. dumetorum'' are considered an underutilized food source as the tuber is high in starch and nutrients. Nonetheless, the bitter yam species remains economically and culturally significant in the region. Additionally, the yam is observed to harden after harvest, a characteristic which decreases its appeal for consumers. Microscopy of yams post harvest has demonstrated that the hardening of the tuber is due to the thickening of cell walls. The rate of hardening is dependent on how ''D. dumetorum'' is stored. To avoid post harvest hardening trifoliate yam is frequently ground into flour after harvesting. Bitter yam can be consumed whole, boiled, or fried. Flour made from the tuber is used to make unleavened bread or to make porridge. The seeds can also be eaten but must undergo a detoxification process and are then dried.


Vernacular names

Local names for ''D. dumetorum'' in West African languages: *
Volta–Niger languages The Volta–Niger family of languages, also known as West Benue–Congo or East Kwa, is one of the branches of the Niger–Congo language family, with perhaps 70 million speakers. Among these are the most important languages of southern Nigeria ...
** Owere language (
Igboid Igboid languages constitute a branch of the Volta–Niger language family. The subgroups are: * Ekpeye * Nuclear Igboid: Igbo, Ikwerre, Ika, Ngwa, Izii– Ikwo–Ezza– Mgbo, Ogba and Ukwuani-Aboh-Ndoni Williamson and Blench conclude th ...
): ''ɔ̀nà'' **
Yoruba language Yoruba (, ; Yor. '; Ajami: ) is a language spoken in West Africa, primarily in Southwestern and Central Nigeria. It is spoken by the ethnic Yoruba people. The number of Yoruba speakers is roughly 50 million, plus about 2 million second-languag ...
: ''èsúrú'' ** Ìjẹ̀bú language: ''èsè'' *
Benue–Congo languages Benue–Congo (sometimes called East Benue–Congo) is a major branch of the Volta-Congo languages which covers most of Sub-Saharan Africa. Subdivisions Central Nigerian (or Platoid) contains the Plateau, Jukunoid and Kainji families, and Banto ...
** Ibibio language: ''ánêm'' **
Tiv language Tiv is a Tivoid language spoken in some states in North Central Nigeria, with some speakers in Cameroon. It had over 5 million speakers in 2020. The largest population of Tiv speakers are found in Benue state in Nigeria. The language is also w ...
: ''ínímbe'' ** Duala language: ''mbá'' ** Boyela language (
Bantu Bantu may refer to: *Bantu languages, constitute the largest sub-branch of the Niger–Congo languages *Bantu peoples, over 400 peoples of Africa speaking a Bantu language * Bantu knots, a type of African hairstyle * Black Association for Nationa ...
): ''moma''


See also

* Yam production in Nigeria


References

Crops originating from Africa Flora of West-Central Tropical Africa Flora of Nigeria dumetorum {{monocot-stub