Diversity and endemism of angiosperms in the Gulf of Guinea islands

The richness of flowering plants (1666 native taxa) and the originality of the flora of the islands of the Gulf of Guinea are remarkable. The flora of Bioko shows the highest diversity in terms of families, genera and species of angiosperms but, due to its proximity to the mainland, the level of endemism is relatively low. The number of endemics in the four islands has suffered a decrease in the last years, due to taxonomic changes. Currently, 176 endemic taxa of angiosperms are recognized. Most of the endemic taxa are under-collected and information is lacking on their biology and distribution, hence the need for inventory work on the flora of the islands. A measure of the similarity between the floras of the islands can be given by determination of genera in common. The results are comparable to those obtained with Exell and Wild's quotient of affinity and show a great similarity between neighbouring islands. The presence of afromontane elements and several palaeoendemics in the mountain rain forest of the islands is notable and makes the study of its flora a priority for research.