Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Common name(s): [more details]

English: Zanzibar yam

Habit:  vine

Description:  "Tuber perennial, becoming very large in age, depressed globose, flattened below, hollowed towards the center, developing roundish lobes in age, up to 40 cm in diameter and 15 cm deep, the upper surface near ground-level.  Plant glabrous.  Twining stems 25 m or more long.  Leaves normally opposite; petiole 8-12 (-26) cm long; blade heart-shaped, up to 20 (-46) cm long (including acumen) and 23 (-58) cm broad, with a thickened acute acumen 5 (-20) cm long; towards base of stem leaves replaced by fleshy auricles; leaf-blades of young plants variously shaped and lobed.  Aerial tubers irregularly roundish, up to 6 cm diameter, deep purplish.  Inflorescences pendulous, spicate.  Male 1 or 2 per leaf-axil or forming a terminal leafless panicle; spikes up to 50 cm long, with 1 or 2 downwardly directed flowers at each node, not opening wide, ± 5 mm long.  Stamens 6.  Female inflorescences 1-3 per leaf-axil, up to 48 cm long; flowers solitary at a node, directed downwards; perianth not opening wide, 177; 3 mm in diameter.  Ovary ± 6 mm long.  Capsule ± 5 cm long and 2.5 cm in diameter, directed upwards.  Seeds winged at both ends, ± 3.5 cm long" (Milne-Redhead, 1975; pp. 7-9).

Habitat/ecology:  In east Africa, "Lowland rain-forest, riverine forest, Acacia woodland, coastal evergreen bushland; often persisting in secondary vegetation; 0-900 m" (Milne-Redhead, 1975; pp. 7-9).

Propagation:  Seed

Native range:  "Ivory coast to the Sudan, south to Angola, Rhodesia and Mozambique, also in Madagascar" (Milne-Redhead, 1975; pp. 7-9).

Presence:

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Singapore Singapore	Singapore (Republic of)		Rejmánek, M. (1996)
Singapore Singapore	Singapore (Republic of)	introduced invasive	Chong, Kwek Yan/Tan, Hugh T. W./Corlett, Richard T. (2009) (p. 34) Naturalised

Comments:  Reported to be an invasive species in Singapore per Rejmánek, 1996.

Control:  Control information from the Bugwood Wiki.