Dioscorea piscatorum (PROSEA)
Dioscorea piscatorum Prain & Burkill
- Family: Dioscoreaceae
Dioscorea borneensis R. Knuth.
- Fish-poison yam (En)
- Indonesia: tuba gunjo (Batak)
- Malaysia: tuba ubi (Peninsular), tubah podeh gantung (Borneo).
Peninsular Malaysia, northern Sumatra, Borneo.
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 .
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.
L.E. Groen, J.S. Siemonsma & P.C.M. Jansen