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13: Spices

Dioscoreophyllum cumminsii (Stapf) Diels

MENISPERMACEAE

Dioscoreophyllum lobatum Diels, Rhophalandria cumminsii Stapf, Rhophalandria lobatum C.H. Wright.

West African serendipity berry, Guinea potato (En). Patate du Golfe de Guineé (Fr).

Originating from tropical Africa (West, Central and southern); occasionally cultivated (e.g. in Ghana), also elsewhere.

The fruits are edible and used to sweeten food; they contain a sweet-tasting protein (monellin) with a sweetening power of more than 3000 times that of sugar. The fruits are stable and can be stored for weeks at room temperature without losing their sweetness. The tubers can be eaten like potatoes. In Gabon the pungent peel of the roots is used to cure wounds, the softened stem devoid of hairs is applied as a plaster on swollen limbs and the viscid sap of the stem is applied to extract abscesses and spines and as a wash against venereal diseases; the root is considered as a sexual stimulant.

Herbaceous to woody, dioecious liana with tuberous rhizome and hairy stems. Tubers about 2 cm in diameter, whitish. Leaves alternate; petiole 6-15 cm long; blade entire or lobed, in outline ovate-triangular, 9-20 cm long and wide, sagittate-cordate at base, acuminate at apex, glabrescent, palmately veined. Inflorescence an axillary raceme, male one up to 30 cm long, female one to 10 cm long; flowers without petals, yellow-green; male flowers with 6-8 sepals in 2 whorls and 3-6 stamens fused into a synandrium; female flowers with 6 sepals and 3-6 carpels with thickened recurved stigmas. Fruit a small, subovoid drupe, up to 3.5 cm long on a peduncle 1 cm long; exocarp smooth, shiny yellow-red, endocarp crustaceous. Seed 1.5-3 cm long. Dioscoreophyllum cumminsii occurs in primary and secondary densely closed vegetation, often in old plantations. Several varieties have been distinguished, mainly based on leaf form and hairiness. Propagation is possible by seed and by tubers. Germination of seed is inhibited by light; pretreating the seed with 0.1-0.5% gibberellic acid solution accelerates germination. Dioscoreophyllum cumminsii is potentially useful for South-East Asia as a source of an intense natural sweetener for the food industry and for low-calorie diets for diabetics and dieters. Other potential sources of natural sweeteners are: Synsepalum dulcificum (Schum. & Thonner) Baillon (miraculous berry, containing miraculin) and Thaumatococcus daniellii (Bennet) Benth. (katemfe, containing thaumatin).

[1] Abbiw, D.K., 1990. Useful plants of Ghana. West African uses of wild and cultivated plants. Intermediate Technology Publications and the Royal Botanic Gardens, Kew, London, United Kingdom. 337 pp.
[28] Flora Zambesiaca (various editors), 1960 . Vol. 1 . Crown Agents for Overseas Governments and Administrations, London, United Kingdom.
[41] Holloway, H.L.O., 1977. Seed propagation of Dioscoreophyllum cumminsii, source of an intense natural sweetener. Economic Botany 31: 47 50.
[46] Inglett, G.E. & May, J.F., 1968. Tropical plants with unusual taste properties. Economic Botany 22: 326 331.
[60] Mansfeld, R., 1986. Verzeichnis landwirtschaftlicher und gärtnerischer Kulturpflanzen (ohne Zierpflanzen) [Register of agricultural and horticultural plants in cultivation (without ornamentals)]. Schultze-Motel, J. et al., editors 2nd edition, 4 volumes. Springer Verlag, Berlin, Germany. 1998 pp.
[89] Summerfield, R.J., Most, B.H. & Boxall, M., 1977. Tropical plants with sweetening properties: physiological and agronomic problems of protected cropping 1. Dioscoreophyllum cumminsii. Economic Botany 31: 331 339.
[97] Walker, A.R. & Sillans, R., 1961. Les plantes utiles du Gabon [The useful plants of Gabon]. Encyclopédie Biologique 56. Éditions Paul Lechevalier, Paris, France. 614 pp.

P.C.M. Jansen

Jansen, P.C.M., 1999. Dioscoreophyllum cumminsii (Stapf) Diels. In: de Guzman, C.C. and Siemonsma, J.S. (Editors): Plant Resources of South-East Asia No 13: Spices. PROSEA Foundation, Bogor, Indonesia. Database record: prota4u.org/prosea