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.
The Neolithic Revolution, also known as the First Agricultural Revolution, was the wide-scale transition of many human cultures during the Neolithic period in Afro-Eurasia from a lifestyle of hunting and gathering to one of agriculture and settlement, making an increasingly large population possible. These settled communities permitted humans to observe and experiment with plants, learning how they grew and developed. This new knowledge led to the domestication of plants into crops.
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 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.
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.
White yam refers to at least two plants in the genus Dioscorea:
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 sansibarensis is a species of flowering plant in the yam family known by the common name Zanzibar yam. It is native to Madagascar and to tropical Africa from Tanzania west to Guinea and south to Mozambique, and it is known elsewhere as an introduced species.
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.
One of the major human migration events was the maritime settlement of the islands of the Indo-Pacific by the Austronesian peoples, believed to have started from at least 5,500 to 4,000 BP. These migrations were accompanied by a set of domesticated, semi-domesticated, and commensal plants and animals transported via outrigger ships and catamarans that enabled early Austronesians to thrive in the islands of Maritime Southeast Asia, Near Oceania (Melanesia), Remote Oceania, Madagascar, and the Comoros Islands.
Dioscorea praehensilis is a species of yam in the genus Dioscorea native to Africa. It is the wild progenitor of the West African domesticated crops Dioscorea rotundata and Dioscorea cayennensis. It is a liana with an edible tuber root found in African rainforests and seasonal tropical forests. The roots reach their maximum starch reserves during the dry season. The species renews its stems every year at the start of the rainy season.
