The name sounds harmless, even laughable. But air potatoes are anything but funny. Established in the United States by gardeners who admired its attractive leaves, it soon spread beyond garden borders and is now wreaking havoc on wild lands by displacing native species.
We spoke with Barry Rice, Invasive Species Specialist for The Nature Conservancy's Global Invasive Species Initiative, about the air potato, how the Conservancy is working to control it and how you can help.
nature.org: What are air potatoes?
Barry Rice: The air potato is a plant native to Asia and Africa, where it is an important food crop. It was first sent to Florida in 1905 for evaluation as a horticultural crop. Reports from scientists and horticulturalists warned about how quickly it spread. Even so, it was promoted as a garden plant, and is still grown by curious gardeners although the strains in the United States are not flavorful — they are bitter and some are potentially poisonous.
Air potato gets its strange common name because it produces little warty potato-like tubers (actually, bulbils) on its vining stems. Its scientific name is Dioscorea bulbifera.
nature.org: Why is the air potato a threat?
Barry Rice: It is a vining, climbing plant that clambers into shrubs and trees. Air potato can even reach the tops of trees that are 60 or more feet tall! It’s not a delicate little plant — it blankets everything it grows on, and the plants beneath it starve for sunlight.
This is a particularly damaging plant in southern Florida, where it invades and harms pinelands and especially the biologically diverse hardwood hammocks. If you’ve ever seen kudzu blanketing a roadside, you can use that image to visualize what air potato can do to the Florida hammocks.
nature.org: How are they spread?
Barry Rice: Air potatoes are grown by gardeners who like it for its vining habit and foliage. Even a quick internet search will unearth lots of people willing to sell tubers or live plants. There is no denying that its heart-shaped leaves are attractive and that it is a pretty plant. That is, until you’ve seen what it can do to wild lands.
Once air potato becomes established in the wild, it begins producing countless little bulbils on its stems. Even a bulbil as small as your fingernail will sprout and result in a new plant. Bulbils can float and travel long distances. Once just a problem for Hawaii and Florida, the plant is now spreading along the Gulf Coast and is showing up in other areas too.
nature.org: What is the Conservancy doing about it?
Barry Rice: Preventing the spread of invasive species is one of the Conservancy’s global priorities. We work on our own lands as well as coordinate with other private and public land managers to control this and other invasive species on wild lands. The best and most cost effective way to stop the spread of invasive species is to prevent the introduction from happening in the first place.
We coordinate with state agencies, invasive pest plant councils and local groups to halt the further spread of air potato by educating people about this plant's harmful affects. We also support the development of legislation passed by states including Florida and Alabama that makes the introduction or possession of these plants unlawful. Organized control efforts help boost public awareness, such as our recent Great Air Potato Roundup near Jacksonville, Florida.
nature.org: What can I do about it?
Barry Rice: Don’t plant it in your garden, don’t let your loved ones plant it, don’t let your friends plant it! It’s just too damaging to our wild lands. If you live in an area that has some invaded areas, you can help by pitching in during a roundup — contact your local Conservancy office for more details. And if you don’t live near an invasion, you can always send the Conservancy a donation to help with their work.September 16, 2011
Dr. Barry Rice is an invasive species specialist with The Nature Conservancy based in Davis, California. He is also the Director of Conservation for the International Carnivorous Plant Society and edits the peer reviewed botanical journal Carnivorous Plant Newsletter. His first book on carnivorous plants was published by Timber Press in 2006.