Hundreds of varieties of sweet potatoes are grown throughout the world. Common to all of these is skin in some shade of brown, with smooth, hairlike roots. The shape is tubular and tapering to a point at both ends. Flesh color varies from white to deep orange to purple.

Tubers with purple flesh are considered the finest; those with deep orange flesh are generally more moist and sweeter than the pale varieties, which can be mealy and dry. Check carefully for signs of rot, as these tubers do not keep well once they are out of the ground.