General Information

COMMON NAMES: Air-Potato, Aerial Yam, Bitter Yam, Air-Yam, Bulbil Yam, Common Yam, Devil's-Potato; German Yamswurzel TRADITIONAL NAMES: ‘Oi (RR MG AT MK AK), ‘Oi Makatea (MT); Other Polynesian - Ufi (SAM) GLOBAL DISTRIBUTION: NATIVE se.Asia; EXOTIC EXOTIC in ancient times, westward to Africa and eastward to Melanesia and Polynesia COOK ISLANDS STATUS: Introduced - Polynesian, Naturalised; Land, lowlands - mountains (+++) SIGNIFICANCE LIST: Food (former Root); Poisonous to eat raw - serious KEY FEATURES: The ‘Oi (Bitter Yam) is a high-climbing, naturalized vine, which is occasional and widespread in the inland forests at lower elevations. The large, alternate, heart-shaped leaves (< 25 cm) have a sharp tip, and several conspicuous longitudinal veins. The dark bulbils (aerial tubers, < 8 cm) develop at the base of the leaf-stalks. Both the bulbils and the root tubers of this Polynesian introduced yam were formerly important foods.

Cook Islands Distribution

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Southern Group: Present    Makatea: Present
RR	MG	AT	MK	MT	AK	PL	TK	MN
+++	+++	P	P	P	++	-		-

Northern Group:
TN	MH	RK	PK	NS	SW
-	-	-	-	-	-

Dioscorea bulbifera Linnaeus
SYNONYMS: Dioscorea sativa [sensu TC]

TAXONOMY: PLANTAE; ANTHOPHYTA (=Angiospermae); LILIOPSIDA (=Monocotyledones); LILIIDAE; Liliales; DIOSCOREACEAE

SIGNIFICANCE NOTES -
POSITIVE SIGNIFICANCE: Food (former Root)
NEGATIVE SIGNIFICANCE: Poisonous to eat raw - serious. Comments: In Asia detoxification methods, involving water extraction, fermentation and roasting of the grated tuber are used for bitter cultivars of this yam. The bitter principles of D. bulbifera include a 3furanoside norditerpene called diosbulbin. These substances are toxic, causing paralysis. Extracts are sometimes used in fishing to immobolize the fish and thus facilitate capture. Toxicity may also be due to saponins in the extract. Zulus use this yam as bait for monkeys and hunters in Malaysia use it to poison tigers. In Indonesia an extract of D. bulbifera is used in the preparation of arrow poison (Coursey, 1967).

Vouchers:
None Recorded.

References:
p.1437 Wagner et al.- Flowering Plants of Hawaii
p.230 Neal - In Gardens of Hawaii
p.393 Tropica
p.1/168 A.C.Smith - Flora Vitiensis Nova
p.299 A Cheeseman - Flora of Rarotonga
p.31 Wilder - Flora of Rarotonga
p.385d Whistler - Ethnobotany of the Cook Islands
p.87 McCormack/Kunzle - Rarotonga's Mountain Tracks and Plants

Data Update History (information):
zTX, zB02, zM02, zupM05a, zD02

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