Ipomoea macrorhiza
Ipomea macrorhiza is an extremely rare species of tuberous, night-blooming morning glory native to the Southeastern United States. Description
This is a vigorous vine with stems growing up to 20 feet long. It has large, tuberous roots and white-and-pink flowers that bloom at night. The leaf shape is highly variable, ranging from triangular to palmate. The seed capsules contain 3-5 pubescent seeds. Cultivation
This plant is rare and so is not widely cultivated. However, its roots are edible and the plant was cultivated by Native Americans as a food source. I. macrorhiza is also of ornamental value due to its attractive flowers. References

Night-blooming plants
macrorhiza