Wild Sweet Potato (Ipomoea pandurata)

Morning Glory family (Convolvulaceae)

Description: This perennial plant consists of a twining vine up to 20-30' long. It will climb adjacent vegetation readily, or sprawl across the ground in open areas. The terete stems are usually hairless, but sometimes pubescent, and often reddish purple. Along the stems are alternate leaves up to 6" long and 4" across. These leaves are usually cordate and hairless, although sometimes the smaller leaves are ovate. They have long hairless petioles and smooth margins. Both the upper and lower surfaces of the leaves are olive green, while the petioles are often reddish purple.

Flowering stalks develop from the axils of the leaves; each flowering stalk has a cluster of 1-5 funnelform flowers. The corolla of each flower is white, except for rosy pink or reddish purple coloration deep within its throat. The corolla has 5 shallow lobes; it is about 2½-3" across when it is fully open and similarly in length. The stamens of the flower are white; they project slightly from the throat of the corolla. The blunt overlapping sepals are light green, hairless, and about ½-¾" long; they often have narrow ridges. The flowers bloom during the morning (or during the afternoon on cloudy days), and they are individually short-lived. However, a typical plant will bloom for about 2 months during mid- to late summer. Each flower is replaced by a 2-celled capsule that contains 2-4 seeds. These flat seeds are conspicuously hairy along their outer edges, and pubescent elsewhere. The root system produces a large tuber that can lie several feet beneath the ground surface and weigh up to 20-30 lb.

Cultivation: The preference is full to partial sun and mesic to dry conditions. The type of soil is not particularly important; this plant often grows where there are rocky or gravelly slopes. Growth can be rampant where the soil is moist and fertile; this plant can smother surrounding vegetation and it prefers some kind of structural support. Drought resistance is very good.

Range & Habitat:This plant is more often seen in disturbed habitats, but it can be found in higher quality habitats as well.

Photographic Location: Wilson County, TN

Faunal Associations: The flowers primarily attract long-tongued bees, including honeybees, bumblebees, and digger bees (Melissodes spp.). Some oligolectic bees that visit the flowers of the Wild Sweet Potato and other Ipomoea spp. include Melitoma taurea (Mallow Bee) and Cemolobus ipomoea (Morning Glory Bee). These insects seek nectar primarily, although the oligolectic bees collect pollen as well.  Because the foliage is bitter and somewhat toxic, it is avoided by mammalian herbivores as a food source. Because its long leafy stems often form dense thicket tangles, Wild Sweet Potato provides excellent cover for birds and other kinds of wildlife during the summer and early fall.