Purple sweet potato is a variety of sweet potato (Ipomoea batatas) with vivid purple flesh, distinct from purple potato, which is a different species (Solanum tuberosum) with a starchier, less sweet flesh. Native to Central and South America, it later spread to the Ryukyu Islands of Japan, including Okinawa, where it became a dietary staple and is also known as the Okinawan or Hawaiian sweet potato. The flesh has a sweet, earthy flavor that is less cloying than orange-fleshed sweet potato, with a dense, creamy texture when cooked. It is prepared much like other sweet potatoes - boiled, steamed, roasted, or mashed - and is used in Okinawan pastries such as beni-imo tart and in Hawaiian desserts. Choose firm, blemish-free tubers with even color; cooking times run slightly longer than for orange-fleshed varieties because of the denser flesh.