The Imatong Mountains have a rich biodiverse flora with much endemism; 1145 species of vascular plant have been recorded here including 110 species of fern. The plains and the lower parts of the mountains are covered by deciduous woodland, wooded grassland and bamboo thickets, while the areas to the east and southeast are in the rain shadow of the mountains, with dry subdesert grassland or deciduous or semi-evergreen bush. The plant diversity of the mountains is due to their position between the West African rain forest, the Ethiopian plateau and the East African mountains, coupled with their relative isolation for long periods during which new species could emerge.