Disocorea bulbifera, the air potato (also known as potato yam and air yam) is native to tropical Africa, Asia, the Pacific Islands and northern Australia and now naturalized throughout the West Indies and tropical America. With it sensitivity to freezing temperatures it is only found in Hawaii, Texas, Louisiana, Mississippi, Alabama, Georgia and Florida. In Florida, it can be found from Monroe County to Escambia County in the western panhandle. Often found on disturbed sites, it also invades natural habitats including hammocks and pinelands.
It is believed that the air potatoes were introduced to the Americas from Africa during the slave trade. In 1905 a sample from the USDA was sent to Florida as an ornamental for assessment. Under Florida’s growing conditions, immediately it’s rampant growth and potential invasiveness was noted. Vines form impenetrable thickets that overgrow, break and sometimes topple trees and shade out smaller native understory plant alter the community ecology. In 1999 it was added to Florida’s noxious weed list.
The Air potato is an aggressive, herbaceous vine that can attain lengths of sixty feet in a single growing season. There may or may not be underground tubers. It’s slender stems twine to the left and is round to slightly angled in cross sections. Leaf arrangements are consistently alternate. It has thin textured, glabrous (hairless) leaves, measuring from two to ten inches long. They are cordate (heart-shaped) with broadly rounded basal lobes, elongated tips, and entire margins. Venation is conspicuous on the upper leaf surface, with arching primary veins originating from the sinus at the base of the blade. Secondary veins run between adjacent pairs of primary veins, giving the leaf surface bullate (puckered or quilted) appearance. The petioles (leaf stalks) are almost as long as the leaf blades. They have a flattened upper surface and flare out to form ruffled wings at the junction with the blade.
In Florida, it is not uncommon for the air potato to flower during its growing season from late summer through early winter. In Florida, there is no sexual reproduction or seed production. The plants reproduce asexually by mean of bulbils (aerial tubers). One to four bulbils is produced at each leaf axil. A single plant is capable of producing two hundred bulbils in a growing season. Their name comes from their potato-like appearance. The bulbils many are brown with a warty texture or light tan to gray with a smooth skin.
In traditional folk medicine in its native range, both the underground and aerial tubers are used. They may be consumed after processing to remove bitter, potentially toxic constituents. There are domesticated varieties that produce edible tubers. The variety that is naturalized in Florida and contains several potential toxins, including alkaloids, saponins, and tannins. It should be regarded as poisonous.