Origin
Southeast Asia
Ecological Impact
Listed as a Category I invasive species for all regions of Florida by the Florida Invasive Species Council and as a Noxious Weed by the Florida Department of Agriculture & Consumer Services. Naturalized populations increasing in number and size in north Florida, with some strands forming blankets of shingled leaves over native vegatation and even able to cover mature trees (D. Ward, University of Florida, 1997 personal communication). So far reported as disrupting natural-area plant communities, particularly coastal hammocks, in south Florida: Broward, Dade, and Lee counties (EPPC 1996).
Description
Vigorously twining herbaceous vine, from massive underground tuber. Stems to 10 m (30 ft) or more in length, freely branching above; internodes square in cross section, with corners compressed into “wings,” these often red-purple tinged. Aerial tubers (bulbils) formed in leaf axils (not as freely as in D. bulbifera), elongate, to 10 cm (4 in) x 3 cm (1.2 in), with rough, bumpy surfaces. Leaves long petioled, opposite (often with only 1 leaf persistent); blades to 20 cm (8 in) or more long, narrowly heart shaped, with basal lobes often angular. Flowers small, occasional, male and female arising from leaf axils on separate plants (dioecious species), male flowers in panicles to 30 cm (1 ft) long, female flowers in smaller spikes. Fruit a 3-parted capsule; seeds winged.
Identification Tips
May be confused with D. bulbifera L., which has small or absent underground tubers, more numerous aerial tubers, and alternate leaves (see next pages). Native wild yams D. floridana and D. villosa are infrequent in hammocks and floodplains of north and west Florida, never form aerial tubers, and have leaf blades that are rarely to 15 cm (6 in) long.
History
Introduced to the Americas by Portuguese and Spanish traders in the 1500s. Introduced to Florida for ornament and escaped from cultivation.
Range
Statewide
Prevention/Management Strategies
Do not plant. Remove plant, tubers and root system.