Okomu is a botanist’s delight, being one of the best examples of the remaining natural tropical lowland rainforest , which previously covered most of the southern part of Nigeria. The vegetation is characterized by a mosaic of swamp-forest, high forest, secondary forest and open scrub. With mean annual rainfall in excess of 2100mm per year, high humidity (65%) and mean monthly temperature of 30,2 deg C, it is the perfect environment for a number of rare plant species. The forest is semi-deciduous. Common trees include the giant mahogany (entandrophragma cylindricum) a large high forest tree strombosia glaucescens, klainedoxa gabonensis, pterocarpus osun, and spathodea campanulata. There are several species endemic to mid-western forests.

Many plants are used for medicinal purposes by the local population. The following checklist is included for interest - Okomu does not recommend that you try out these medicines yourself unless advised by a reputable ethnobotanist!