Pacific Island Ecosystems at Risk (PIER)

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Dioscorea sansibarensis
Pax, Dioscoreaceae
No images for this taxon

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).


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

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

Control:  Control information from the Bugwood Wiki.

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This page was created on 1 JUL 2004 and was last updated on 25 JUN 2009.