Chinese yam
Dioscorea polystachya Turcz.
Description from Invasive.org
- Appearance
- Dioscorea polystachya is an invasive herbaceous, twining vine that grows to about 16.4 ft. (5 m). It invades open to shady areas in the Eastern United States.
- Foliage
- The leaves are alternate proximally but can become opposite as they advance up the vine. They are about 3 to 6 inches long, 3 to 4 inches wide and heart to fiddle shaped (margins three-lobed), with prominent, parallel veins. The petiole base is not clasping. Leaves are usually more rounded when young or on young plants and fiddle shaped farther along the stem and on older plants. The rounded stems are thin and wiry.
- Flowers
- The staminate plants may produce small, white flowers annually.
- Fruit
- The seeds are winged all around, but the chief means of reproduction are aerial, potato-like tubers (bulbils) located at the leaf axils and underground tubers.
- Ecological Threat
- Dioscorea polystachya can form dense masses of vines that cover and kill native vegetation, including trees, within a variety of moist, disturbed habitats. It was introduced from Asia for ornamental, food, and medicinal purposes and escaped cultivation in the mid-1990s.
Resources
- A Field Guide for the Identification of Invasive Plants in Southern Forests - USDA Forest Service
- Southeast Exotic Pest Plant Council Invasive Plant Manual - SE-EPPC
- Element Stewardship Abstract - The Nature Conservancy
- Weed of the Week - USDA Forest Service
- Plant Invaders of Mid-Atlantic Natural Areas - National Park Service
Selected Images from Invasive.org
View All Images at Invasive.org
Feature(s) Aerial tubers and foliage
Jack Ranney, University of Tennessee, Bugwood.org
Additional Resolutions & Image Usage
Jack Ranney, University of Tennessee, Bugwood.org
Additional Resolutions & Image Usage
Plant(s)
Great Smoky Mountains National Park Resource Management , USDI National Park Service, Bugwood.org
Additional Resolutions & Image Usage
Great Smoky Mountains National Park Resource Management , USDI National Park Service, Bugwood.org
Additional Resolutions & Image Usage
Plant(s)
Troy Evans, Great Smoky Mountains National Park, Bugwood.org
Additional Resolutions & Image Usage
Troy Evans, Great Smoky Mountains National Park, Bugwood.org
Additional Resolutions & Image Usage
Fruit(s) aerial tubers
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage
Feature(s) aerial tubers
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage
Chris Evans, University of Illinois, Bugwood.org
Additional Resolutions & Image Usage