Twining lianas are met with in a species of Bignonia; Umbelliferae Ranunculaceae and Cruciferae, are represented by a few fruits.
In the Ghazal province also are many rubber-producing lianas, among them the Landolphia owariensis.
The vegetation on the western side of the island is much less dense, often appearing as scattered clumps of trees on savannah-like plains rather than continuous forest; while in the south-west, where the rainfall is very scanty, the vegetation is largely of fleshy-leaved and spiny plants - aloes and cacti (the latter introduced), with several species of Euphorbia, as well as numerous lianas, one of which (Intisy) yields india-rubber.
In the eastern forests palms, bamboos, lianas and tree-ferns, as well as species of Dracaena, are found.
The most valuable of the forest flora are the lianas, notably Landolphia florida, which yield the india-rubber of commerce.