Landolphia owariensis is a species of liana from the family Apocynaceae found in tropical Africa. Latex can be extracted from this plant for the manufacture of natural rubber. Other names for this vine are eta, the white rubber vine and the Congo rubber plant. Congo rubber was a commercial rubber exported from the Congo Free State starting in 1890, most notable for its forced harvesting under conditions of great human suffering, in the Congo Free State, detailed in the 1904 Casement Report. From 1885 to 1908, millions died as a result of murder, deprivation, and disease, with population falling by millions in this period; some writers estimate this loss to be as high as 10 million people.
Description
When growing in savannah, Landolphia owariensis is an erect bush or small tree, but when growing among trees, it can develop into a woody vine with a stem that grows to a metre wide and long. The bark is rough, dark brown or greyish-brown, and often covered with pale yellow lenticels; it exudes a milky juice when damaged. The leaves grow in opposite pairs and are oblong, elliptical or obovate, up to . The young leaves are reddish at first but the upper sides of the leaf blades later become dark green and glossy, with a pale midrib. The flowers are in terminal panicles. The peduncles and calyx lobes are clad in brown hairs, and the corolla tube and lobes are yellowish, pinkish or white. The flowers are followed by rounded, wrinkled fruit resembling oranges. These are juicy and slightly acid when ripe, with usually three seeds surrounded by soft, edible pulp.
The main trunk soon divides into several stout stems which repeatedly branch as they clamber over their host trees. After the fruit have fallen, the stems elongate into tendrils which wist spirally and secure the vine to its host.
Distribution and habitat
Landolphia owariensis is native to the tropics of Africa, its range extending from Guinea in West Africa to Sudan and Tanzania in East Africa. When growing in open savannah it takes the form of a bush, but in forested areas it becomes a vine and can climb trees, reaching heights of or more. It has a rhizome which can survive bush fires, readily throwing up shoots which flower and fruit at a young age even before the twigs have become lignified.
Uses
The fruit are gathered for human consumption, and are either eaten fresh or fermented into an alcoholic beverage.
The latex used to be gathered for the manufacture of rubber. The latex coagulates rapidly after extraction, and one traditional method of collection was to make an incision on the stem and allow the latex to trickle onto the gatherer's hand and arm where it rapidly coagulated. When this process had been repeated several times, the rubber "sleeve" was unrolled off the arm. The latex has been used to mix with the ground up seeds of Strophanthus to make arrow poison, and to glue the poison to the arrow-head. The latex is also used by itself as a birdlime to catch small birds and animals.
Landolphia owariensis has been used extensively in traditional medicine, with the leaves and stems being used as an anti-microbial, and in the treatment of venereal disease and of colic. Other uses include as a vermifuge, a purgative, an analgesic and an anti-inflammatory. A decoction prepared from the leaves is used against malaria and as a purgative; the bark is used against worms and an extract of the roots against gonorrhea. The latex that oozes from wounds can be drunk, or used as an enema to treat intestinal worms.
In modern times Landolphia owariensis is primarily used for its fruits, but occasionally for rubber band production; it was a major source for rubber from nations including Sierra Leone, Ghana, and Nigeria in the early 1900s.
