Cassava is a root vegetable. It is the underground part of the cassava shrub, which has the Latin name Manihot esculenta. Like potatoes and yams, it is a tuber crop. Cassava roots have a similar shape to sweet potatoes. People can also eat the leaves of the cassava plant.Cassava is a calorie-rich vegetable that contains plenty of carbohydrate and key vitamins and minerals. Cassava is a good source of vitamin C, thiamine, riboflavin, and niacin. The leaves, which are also edible if a person cooks them or dries them in the sun, can contain up to 25 percent protein.