Yalu River, a river in eastern Asia, forming part of the border between North Korea and China. The Yalu is about 500 miles (800 km) long. It flows from the Changbai mountains southwestward to Korea Bay, an arm of the Yellow Sea. The Yalu is used for generating hydroelectric power and for navigation.
Yam, the name of a climbing vine and its edible tuberous roots. There are more than 500 species, most of them found in tropical and subtropical regions. Yams are grown in deep, well-drained soil. The tuberous roots weigh up to 30 pounds (14 kg) and are rich in carbohydrates. They are eaten boiled, fried, or roasted. They are also ground into flour. Some species are used as livestock feed, others are grown as ornamentals. One species yields a drug that is used in some oral contraceptives. The word "yam" is often used to refer to the sweet potato, a similar but unrelated plant.
The many species of yams make up the genus Dioscoreaof the family Dioscoreaceae.