yams (Dioscorea)

  • This page is provided for interest and information purposes only, as you cannot eat the true yam raw because it can make you sick. In the west the "sweet potato" is called a "yam", but this is a different plant. You can find out more about sweet potatoes here sweet potatoes
  • The true yam is a member of the Dioscoreaceae family. It has a root which is a potato-like tuber. The plant grows up like a vine. It produces nodules known as "tubercles" hanging on the vine structure. These can be used for propagation or food purposes.
  • In West Africa, the yam tuber grows to about 1.5 metres long. It's an important crop in West Africa, particularly Nigeria, and also New Guinea. These tubers can last for 6 months kept dry without refrigeration.
  • You can buy prepared and dried powdered yam in specialist African supply shops. This is typically mixed with water and prepared and used like an instant mashed potato.
  • In the United States and Canada the sweet potato (Ipomoea batatas) is called a yam, so recipe books from these regions refer to the sweet potato when they specify yam.
  • In New Zealand, the root crop that they call a yam is technically not a true yam but is a member of the Oxalis family. The New Zeeland "yam" yields a small, thumb sized, pink sweet tuber. There are other varieties with different colours. These are usually smaller.
  • In the Philippines, purple yams (Dioscorea alata) are used to make the Ube Halaya dish. This is a mixture of cooked purple yams, coconut milk and some form of sweetner.
  • The clip on the right uses the purple yam Dioscorea bulbifera. I'm not sure what this plant is.
  • There is the Japanese mountain yam (Dioscorea opposita) which, if suitably prepared to remove the oxalate, can be eaten raw.