White sweet potatoes are root vegetables that are used as an important source of starch in many parts of the world. Despite the fact that they are called potatoes, they are not closely related to true potatoes but are in the same genus as the morning glory. There are many varieties of sweet potato and also many varieties of white sweet potato. This name, white sweet potato, is used to describe the color of the flesh and skin of any number of sweet potato breeds.
Nutritionally, the lighter colored sweet potatoes, such as white sweet potatoes, are higher in starch than their darker colored orange, red, or purple counterparts. They have less vitamin A and fewer carotenoids than brightly colored sweet potatoes do and are often less sweet. Nearly all sweet potatoes are classified as Ipomoea batatas, despite the many differences in the varieties of sweet potato that are cultivated. Most other plants in this genus are toxic.
The tuber, or thickened root, is the part of white sweet potatoes that is cultivated for use as a food source. Small shoots and sprouts are also edible but are rarely eaten outside the tropics and subtropics, where these plants flourish. When dug up and removed from the rest of the plant, white sweet potato tubers will keep at room temperature for a number of months, making them an important crop in winter months, when fewer vegetables are able to grow.
Though they used to be more popular, white sweet potatoes have lost popularity to orange sweet potatoes in many parts of the world. Sweet potatoes with more carotenoids tend to be sweeter and softer, which are qualities that have made them desirable for cooking. In many cases, these orange sweet potatoes are called yams, though they are not closely related to true yams at all. Despite the fact that white sweet potatoes are less popular than orange ones, they are still widely available throughout most of the world.
White sweet potatoes are native to South and Central America. They are now grown throughout the world, though it requires soil temperatures of between 70 and 80 degrees Fahrenheit (21.1 and 26.7 degrees Celsius) for them to thrive, making them more suited to tropical or sub-tropical climates. While these plants can be grown from seed, they are more frequently cultivated from slips, which are pieces of the root of a mature plant.