Root vegetables are underground plant parts eaten by humans as food. Although botany distinguishes true roots from non-roots, the term "root vegetable" is applied to all these types in agricultural and culinary usage.
Dioscorea alata, also known as purple yam, ube, or greater yam, among many other names, is a species of yam. The tubers are usually a vivid violet-purple to bright lavender in color, but some range in color from cream to plain white. It is sometimes confused with taro and the Okinawa sweet potato beniimo (紅芋), however D. alata is also grown in Okinawa. With its origins in the Asian tropics, D. alata has been known to humans since ancient times.
Dioscorea is a genus of over 600 species of flowering plants in the family Dioscoreaceae, native throughout the tropical and warm temperate regions of the world. The vast majority of the species are tropical, with only a few species extending into temperate climates. It was named by the monk Charles Plumier after the ancient Greek physician and botanist Dioscorides.
Dioscorea communis or Tamus communis is a species of flowering plant in the yam family Dioscoreaceae and is commonly known as black bryony, lady's-seal or black bindweed.
Yam is the common name for some plant species in the genus Dioscorea that form edible tubers. The tubers of some other species in the genus, such as D. communis, are toxic. Yams are perennial herbaceous vines cultivated for the consumption of their starchy tubers in many temperate and tropical regions, especially in West Africa, South America and the Caribbean, Asia, and Oceania. The tubers themselves, also called "yams", come in a variety of forms owing to numerous cultivars and related species.
Àmàlà is a staple swallow food native to the Yoruba ethnic group of Southwestern Nigeria. It is made of yam, cassava flour, or unripe plantain flour. Tubers of yams are peeled, sliced, cleaned, dried and then ground into flour. It is also called èlùbọ́. Yams are white in colour but turn brown when dried which gives àmàlà its colour. It is a popular side dish served with ewédú and gbẹ̀gìrì, but is also served with a variety of other ọbè(soups), such as ẹ̀fọ́, ilá, and ogbono.
Dioscorea polystachya or Chinese yam, also called cinnamon-vine, is a species of flowering plant in the yam family. It is sometimes called Chinese potato or by its Korean name ma. It is also called huaishan in Mandarin and waisan in Cantonese.
Dioscorea bulbifera is a species of true yam in the yam family, Dioscoreaceae. It is native to Africa, Asia and northern Australia. It is widely cultivated and has become naturalized in many regions.
Dioscorea trifida is a species of flowering plant in the family Dioscoreaceae. It is a species of yam. It is native to the Caribbean and Central and South America. Its many common names include Indian yam, cush-cush, and yampee. It is called mapuey in Venezuela, inhame in Brazil, tabena and ñame in Colombia, sacha papa in Peru, and ñampi in Costa Rica.
Tacca leontopetaloides is a species of flowering plant in the yam family Dioscoreaceae. It is native to Island Southeast Asia but have been introduced as canoe plants throughout the Indo-Pacific tropics by Austronesian peoples during prehistoric times. They have become naturalized to tropical Africa, South Asia, northern Australia, and Oceania. Common names include Polynesian arrowroot, Fiji arrowroot, East Indies arrowroot, pia, and seashore bat lily.
Dioscorea transversa, the pencil yam, is a vine of eastern and northern Australia.
Dioscorea orangeana, is a tuberous vining flowering plant in the genus Dioscorea, endemic the Forêt d’Orangea near Antsiranana in Madagascar, from which it derives its name. The tuber is possibly edible, and unlike most other Dioscorea species, the tuber has many finger-like lobes as opposed to a single tuber. Because the plant is new to science and the possible harvesting by local populations, the conservation status of Dioscorea orangeana is of great concern.
Nigeria is by far the world’s largest producer of yams, accounting for over 70–76 percent of the world production. According to the Food and Agriculture Organization report, in 1985, Nigeria produced 18.3 million tonnes of yam from 1.5 million hectares, representing 73.8 percent of total yam production in Africa. According to 2008 figures, yam production in Nigeria has nearly doubled since 1985, with Nigeria producing 35.017 million metric tonnes with value equivalent of US$5.654 billion. In perspective, the world's second and third largest producers of yams, Côte d'Ivoire and Ghana, only produced 6.9 and 4.8 million tonnes of yams in 2008 respectively. According to the International Institute of Tropical Agriculture, Nigeria accounted for about 70 percent of the world production amounting to 17 million tonnes from land area 2,837,000 hectares under yam cultivation.
Dioscorea pentaphylla is a species of flowering plant in the yam family known by the common name fiveleaf yam. It is native to southern and eastern Asia as well as New Guinea and northern Australia. It is widely cultivated as a food crop and naturalized in Cuba and on several island chains in the Pacific.
Ube halaya or halayang ube is a Philippine dessert made from boiled and mashed purple yam. Ube halaya is the main base in ube/purple yam flavored-pastries and ube ice cream. It can also be incorporated in other desserts such as halo-halo. It is also commonly anglicized as ube jam, or called by its original native name, nilupak na ube.
Dioscorine is an alkaloid toxin isolated from the tubers of tropical yam on several continents. It has been used as a monkey poison in some African countries, and as an arrow poison to aid in hunting in several parts of Asia. It was first isolated from Dioscorea hirsute by Boorsma in 1894 and obtained in a crystalline form by Schutte in 1897, and has since been found in other Dioscorea species. Dioscorine is a neurotoxin that acts by blocking the nicotinic acetylcholine receptor. Dioscorine is generally isolated in tandem with other alkaloids such as dioscin but is usually the most potent toxin in the mixture. It is a convulsant, producing symptoms similar to picrotoxin, with which it shares a similar mechanism of action.
Scutellonema bradys, also known as yam nematode, is a migratory endoparasitic nematode causing major damage to yam crop in many African tropical regions, as well in parts of South and Central America and Asia. They can cause reduction of 20-30% in tuber weight at harvest.
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.
Dioscorea hispida, also known as the Indian three-leaved yam, 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 edible.
Pounded yam or Iyán (Yoruba) or Ruam-Yo (Tiv) is a Nigerian swallow food native to the Yoruba, Igbo, Tiv and Ebira and the Okun ethnic groups. It is a traditional food. It is prepared by pounding boiled yam with a mortar and pestle. Pounded yam is similar to mashed potatoes but heavier. It is a smooth and tasty delicacy traditionally eaten with the hands.
