The plant is a herbaceous perennial vine, bearing alternate heart-shaped or palmately lobed leaves and medium-sized sympetalous flowers. The stems are usually crawling on the ground and form adventitious roots at the nodes. The leaves are screwed along the stems. The leaf stalk is 5 to 20 inches long. The leaf blades are very variable, 5 to 13 centimeters long, the shape is heart-, kidney- to egg-shaped, rounded or triangular and spear-shaped, the edge can be entire, toothed or often three to seven times lobed, cut or divided. Most of the leaf surfaces are bare, rarely hairy, the tip is rounded to pointed. The leaves are mostly green in color, but due to the accumulation of anthocyanins, especially along the leaf veins, they can be purple in color. Depending on the variety, the total length of a stem can be between 0.5 and 4 meters. Some cultivars also form shoots up to 16 meters in length. However, these do not form underground storage organs. The hermaphrodite, five-fold and short-stalked flowers are single or few in stalked, zymous inflorescences that arise from the leaf axils and stand upright. Some varieties rarely or never produce flowers. The small sepals are elongated and tapering to a point and spiky and (rarely only 7) 10 to 15 mm long, usually finely haired or ciliate. The inner three are a little longer. The 4 to 7 cm long, overgrown and funnel-shaped, folded crown, with a shorter hem, can be lavender to purple-lavender in color, the throat is usually darker in color, but white crowns can also appear. The enclosed stamens are of unequal length with glandular filaments. The two-chamber ovary is upper constant with a relatively short stylus. The flowers open before sunrise and stay open for a few hours. They close again in the morning and begin to wither. The edible tuberous root is long and tapered, with a smooth skin whose color ranges between yellow, orange, red, brown, purple, and beige. Its flesh ranges from beige through white, red, pink, violet, yellow, orange, and purple. Sweet potato cultivars with white or pale yellow flesh are less sweet and moist than those with red, pink or orange flesh.
