Description
Dioscorea alata, known as purple yam or many other names, is a species of yam, a tuberous root vegetable. The tubers are usually vivid violet to bright lavender in colour, hence the common name.
Many different common names from these regions. In English alone, aside from purple yam, other common names include greater yam, Guyana arrowroot, ten-months yam, water yam, white yam, winged yam.
Purple yam is used in a variety of desserts, as well as a flavor for ice cream, milk, Swiss rolls, tarts, cookies, cupcakes, cakes and other types of pastries. In the Philippines, it is known as ube and is often eaten boiled, baked, or as a sweetened pudding called ube halaya the latter is a popular ingredient in the iced dessert called halo-halo. In Maharashtra, the stir-fried chips are eaten during religious fasting.


Medicinal
In folk medicine D. alata has been used as a moderate laxative and vermifuge, and for fever, gonorrhea, leprosy, tumors, and inflamed hemorrhoids. D. alata has relatively high levels of oxalates (486–781 mg/100 g dry matter).

Other uses
The color of purple varieties is due to various anthocyanin pigments.The pigments are water-soluble, and have been proposed as possible food coloring agents.
D. alata is sometimes grown in gardens for its ornamental value.