Merremia tuberosa (PROSEA)

Plant Resources of South-East Asia Introduction

List of species

Merremia tuberosa (L.) Rendle

Protologue: Fl. Trop. Afr. 4(2): 104 (1905).

Family: Convolvulaceae

Synonyms

• Ipomoea tuberosa L. (1753),
• Operculina tuberosa (L.) Meissn. (1869).

Vernacular names

• Wood rose, Brazilian jalap (En)
• Indonesia: areuy kawoyang (Sundanese)
• Vietnam: bìm củ.

Distribution

Probably of Central American origin, now distributed throughout tropical Africa, the Mascarene Islands, India and Sri Lanka; in India and Malesia cultivated as a medicinal and sometimes escaped from cultivation.

Uses

In South-East Asia, the tuber is used as a drastic purgative. The plant is also planted as an ornamental in Africa. The woody fruits are used in flower arrangements in Europe.

Observations

• A perennial, glabrous twiner, 3-5 m long, stems robust, finely striate, tuber large.
• Leaves orbicular in outline, 6-16 cm × 6-16 cm, palmately divided to far below the middle, segments 7, oblong-lanceolate, apex acuminate, base narrowed, entire, the middle segment larger than the lateral ones, petiole 6-18 cm long.
• Flowers in a few-flowered cyme, peduncle 4-15 cm long, bracts triangular, small.
• Flower-buds oblong, apex pointed, pedicel 15-18 mm long, in fruit clavate, up to 5 cm long, sepals subequal, outer ones 25 mm long, ovate, obtuse, inner ones oblong, in fruit 5-6 cm long, enclosing the capsule, corolla funnel-shaped, 5.5 cm long, yellow, anthers twisted.
• Capsule subglobose, 3.5 cm in diameter, pericarp thin, splitting irregularly, and loosening circumsessile at base.
• Seeds 17 mm long, black, black pubescence on sides.

In Indonesia, M. tuberosa occurs from sea-level up to 600 m altitude. The loosening of the capsulewall is different from that of Operculina, where the wall shows 2 layers, and the outer one is fleshy in the upper part, forming an operculum.

Selected sources

• [134] Burkill, H.M., 1985—2000. The useful plants of West tropical Africa. 2nd Edition. 5 volumes. Royal Botanic Gardens, Kew, United Kingdom. Vol. 1 (1985), Families A—D, 960 pp.; Vol. 2 (1994), Families E—I, 636 pp.; Vol. 3 (1995), Families J—L, 857 pp.; Vol. 4 (1997), Families M—R, 969 pp; Vol. 5 (2000), Families S—Z, 686 pp.
• [647] 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.

Main genus page

• Merremia

Authors

• Muhammad Mansur