Manihot esculenta, commonly called cassava, manioc, or yuca, is a woody shrub of the spurge family, Euphorbiaceae, native to South America, from Brazil and parts of the Andes. Although a perennial plant, cassava is extensively cultivated as an annual crop in tropical and subtropical regions for its edible starchy root tuber, a major source of carbohydrates. Cassava is predominantly consumed in boiled form, but substantial quantities are used to extract cassava starch, called tapioca, which is used for food, animal feed, and industrial purposes. The Brazilian farinha, and the related garri of West Africa, is an edible coarse flour obtained by grating cassava roots, pressing moisture off the obtained grated pulp, and finally drying it.
Dioscorea alata – also called 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 and other parts of Yorubaland. 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 esculenta, commonly known as the lesser yam, is a yam species native to Island Southeast Asia and introduced to Near Oceania and East Africa by early Austronesian voyagers. It is grown for their edible tubers, though it has smaller tubers than the more widely-cultivated Dioscorea alata and is usually spiny.
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.
Kokoro is a variety of Dioscorea rotundata yam that are abundant in Western Nigeria, Benin and Togo. Their common use by ethnic groups such as the Yoruba that put heavy pressure on the cultivated land suggest that they have been cultivated since ancient times, since they are the only type of yam that gives good yields on degraded soil. In modern times, Kokoro yams are gaining in importance as the yam chips trade is expanding. The Kokoro variety is essential for preparing peeled and dried yam.
Dioscorea cayenensis subsp. rotundata, commonly known as the white yam, West African yam, Guinea yam, or white ñame, is a subspecies of yam native to Africa. It is one of the most important cultivated yams. Kokoro is one of its most important cultivars.
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.
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 abyssinica is a herbaceous vine in the genus Dioscorea native to several Central African countries including Benin, Burkina Faso, Central African Republic, Eritrea, Ethiopia, Ghana, Ivory Coast, Liberia, Mali, Nigeria, Senegal, and Sudan. The plant's starchy tubers are edible and are either harvested from the wild or cultivated; however, they are difficult to obtain due to the depth at which they grow in the soil. It is propagated by seed.
Helen Nosakhare Asemota is a biochemist and agricultural biotechnologist based in Jamaica. She is Professor of Biochemistry and Molecular Biology and Director of the Biotechnology Centre at the University of the West Indies at Mona, Jamaica. Her research develops biotechnology strategies for production and improvement of tropical tuber crops. She is notable for leading large international biotechnology collaborations, as well as for acting as an international biotechnology consultant for the United Nations (UN).
Dioscorea chouardii is a herbaceous plant in the family Dioscoreaceae. It is endemic to a single cliff located in the Pyrenees of Aragon, Spain.
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.
Dioscorea deltoidea, the Nepal yam, is a species of flowering plant in the family Dioscoreaceae. Its native range is the Himalayas through to south-central China and mainland Southeast Asia. Its tubers contain diosgenin and are harvested by local peoples as a treatment for a variety of conditions, including gastrointestinal disorders and intestinal worms. Tubers are also eaten after boiling, washing, and baking. It grows in forests and humus-rich soils.
