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.

Hevea brasiliensis, the Pará rubber tree, sharinga tree, seringueira, or most commonly, rubber tree or rubber plant, is a flowering plant belonging to the spurge family Euphorbiaceae originally native to the Amazon basin, but is now pantropical in distribution due to introductions. It is the most economically important member of the genus Hevea because the milky latex extracted from the tree is the primary source of natural rubber.