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Exotic Climbing Yams

Air yam Dioscorea bulbifera
Chinese yam , Cinnamon vine D. oppositifolia
(formerly D. batatas)

Plant: Deciduous, high-climbing vines, to 66 ft (20 m) long, infestations covering vegetation (native yam species will not), twining stems with heart-shaped leaves and dangling potato-like tubers (bulbils) at leaf axils in summer to fall, flowers rare, from underground tubers. Monocots.

Stem: Twining and covering vegetation, branching, round or slightly angled in cross section, hairless.

Leaves: Alternate (air yam) or opposite (Chinese yam), heart-shaped to triangular, 4-8 in (10-20 cm) long and 2-6 in (5-15 cm) wide, margins smooth, dark green with slightly-indented curved veins above and lighter green beneath, elongated tips.

Flowers: May-Aug. Rare and flowering at night, small, fragrant, male and female flowers on separate plants, green to white in panicles or spikes to 4.5 in (11 cm) long, axillary.

Fruit and seeds: Year-round. Aerial tubers, small potatoes, in leaf axils, spherical, to 5 in (12 cm) long and 4 in (10 cm) wide.

Ecology: Spread and persist by the abundant production of aerial tubers. Occur on open to semi-shady sites.
Air Yam
September (F. Nation)

July (F. Nation)

Synonyms: air potato.

Resembles greenbrier (Smilax spp.) which has thorns and green to purple berries (no aerial potatoes). Several species of native Dioscorea species do not form dense vine infestations nor aerial tubers (bulbils), which include fourleaf yam , D. quaternata; wild yam, D. villosa (hairy upper leaf surface); and Florida yam, D. floridana.

Exotic Pest Plant Control Recommendations

FIA Code - 3030

July (F. Nation) July (F. Nation)


October (R. Hammer) March (J. Miller)


States with suspected Air
yam infestations are shown in red.*		 States with suspected Chinese
yam infestations are shown in red.*

* USDA, NRCS. 2001. The PLANTS Database, Version 3.1 (http://plants.usda.gov). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. February 5, 2002.

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USDA Forest ServiceUSDA APHIS PPQ The Bugwood Network University of Georgia Invasive.org is a joint project of
The Bugwood Network, USDA Forest Service & USDA APHIS PPQ.
The University of Georgia - Warnell School of Forest Resources and
College of Agricultural and Environmental Sciences - Dept. of Entomology
Last updated on Sunday, August 10, 2003 at 11:13 PM
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