Mid-Atlantic Invaders Tool

Chinese yam

Dioscorea polystachya

Turcz.

Taxon, Habit: Plant, Vine

Habitat: Terrestrial

U.S. Nativity: Introduced

Species Synonym(s): None

Common Name(s): None

Family: Dioscoreaceae (Yam Family)

Family Synonym(s): None

Native Range (GRIN):

Selected images from Bugwood.org

View all images from Invasive.org

Provide your plant image to Bugwood.org

Feature

Jack Ranney, University of Tennessee

Plant

Great Smoky Mountains National Park Resource Management , USDI National Park Service

Infestation

Chris Evans, University of Illinois

Infestation

Chris Evans, University of Illinois

Infestation

Chris Evans, University of Illinois

Foliage

Chris Evans, University of Illinois

Foliage

James H. Miller, USDA Forest Service

Plant

Troy Evans, Great Smoky Mountains National Park

Seed

Steve Hurst, USDA NRCS PLANTS Database

Fruit

Chris Evans, University of Illinois

Foliage

Chris Evans, University of Illinois

Feature

Chris Evans, University of Illinois

Description

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.

Uses

Landscape Ornamental Use (GRIN): Yes

All Uses (GRIN): Ornamental, Starch, Vegetable

Distribution Map (EDDMapS)

Wetland Indicator

Summary: Chinese yam (Dioscorea polystachya) is a Terrestrial species.

Atlantic and Gulf Coastal Plain (AGCP):

Mid-Atlantic Coastal Plain regions

No Data

Eastern Mountains and Piedmont (EMP):

Mid-Atlantic Piedmont and Mountain regions

No Data

Northcentral and Northeast (NCNE):

Northern parts of PA and NJ (and beyond)

No Data


Legend (data from U.S. Army Corps of Engineers)

OBL (Obligate wetland): Almost always occurs in wetlands (estimated probability > 99%) under natural conditions

FACW (Facultative wetland): Usually occurs in wetlands (estimated probability 67% - 99%), but occasionally found in non-wetlands

FAC (Facultative): Equally likely to occur in wetlands (estimated probability 34% - 66%) or non-wetlands

FACU (Facultative upland): Usually occur in non-wetlands (estimated probability 67% - 99%), but occasionally found in wetlands (estimated probability 1% - 33%)

UPL (Obligate upland): Occur almost always (estimated probability > 99%) in non-wetlands under natural conditions

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Order: Dioscoreales
Family: Dioscoreaceae
Genus: Dioscorea
Subject: Dioscorea polystachya Turcz.