BugwoodWiki Article

Chinese yam
Dioscorea polystachya Turcz.

Overview

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 8 in. (20.3 cm) long, 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.

Selected Images


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Chinese yam
Dioscorea polystachya
Feature(s)
Jack Ranney
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Chinese yam
Dioscorea polystachya
Plant(s)
Great Smoky Mountains National Park Resource Management Archive
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Chinese yam
Dioscorea polystachya
Infestation
Chris Evans
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Chinese yam
Dioscorea polystachya
Infestation
Chris Evans
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Chinese yam
Dioscorea polystachya
Infestation
Chris Evans
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Chinese yam
Dioscorea polystachya
Foliage
Chris Evans
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Chinese yam
Dioscorea polystachya
Foliage
James H. Miller
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Chinese yam
Dioscorea polystachya
Plant(s)
Troy Evans
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Chinese yam
Dioscorea polystachya
Seed(s)
Steve Hurst
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Chinese yam
Dioscorea polystachya
Fruit(s)
Chris Evans
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Chinese yam
Dioscorea polystachya
Foliage
Chris Evans
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Chinese yam
Dioscorea polystachya
Feature(s)
Chris Evans

Maps


EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit www.eddmaps.org

EDDMapS Distribution

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit Invasive.org

State Regulated List

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Order: Dioscoreales
Family: Dioscoreaceae
Genus: Dioscorea

Other System Links

Plants: DIOP

Synonyms and Other Names

Related Scientific Names:

Dioscorea batatas L.(Synonym)
Dioscorea oppositifolia L.(Synonym)

Categories

Category: Vines
Category: Forbs/Herbs

References

Common Name Reference:

Scientific Name Reference: Flora of North America. http://www.efloras.org/