Dioscorea piscatorum (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Dioscorea piscatorum Prain & Burkill

Family: Dioscoreaceae

Synonyms

Dioscorea borneensis R. Knuth.

Vernacular names

• Fish-poison yam (En)
• Indonesia: tuba gunjo (Batak)
• Malaysia: tuba ubi (Peninsular), tubah podeh gantung (Borneo).

Distribution

Peninsular Malaysia, northern Sumatra, Borneo.

Uses

Tubers are eaten roasted; if boiled or inadequately baked they remain bitter. The tubers contain a toxic saponin and are used as a substitute for Derris elliptica (Sweet) Bentham as fish poison in fishing and as insecticide to kill parasitic worms in rice. The poison is destroyed by heat and is less effective than that of Derris .

Observations

Perennial, dioecious, glabrous herb with woody, prickly stem, twining to the left. Tubers arising in axils where the base of the stem touches the soil surface, numbering more than one, clavate, unarmed or with short roots becoming thorny, some coming aboveground; skin brown-red, flesh dark red. Leaves simple, chartaceous; petiole shorter than the blade, with scattered small prickles; blade ovate to cordate, up to 18 cm × 14 cm, prominently veined. Flowering and fruiting have rarely been observed, probably because flowering does not occur until the climber has topped the forest.

Selected sources

13, 22.

Authors

L.E. Groen, J.S. Siemonsma & P.C.M. Jansen