Included here is the Congo Basin, eastern Nigeria, eastern Cameroon and the islands of the Gulf of Guinea (Fernando Po, Principe, Sae Tome and Annobon).

Congolian Crater Lakes

Crater lakes occur throughout the Cameroon Highlands. Lake Nyos in the Bamenda Highlands is probably the best known mainly because it released a cloud of poisonous gas in 1986 causing a number of fatalities. However, one of the best studied is Lake Edib but it is far from typical. A mattress of Sphagnum planifolium largely covers the surface water. On top of this is a distinct zonation of vascular plants. In the zone adjacent to open water species such as Cyperus pectinatus, Elaeocharis variegata, Oplismenus hirtellus and Pneumatopteris afra predominate. Moving landward a more species-rich zone occurs with species like Drosera madagascariensis, Habenaria weileriana, Laurembergia tetrandra, Ludwigia abyssinica, Pseudolycopodiella affine, Senecio ruwenzoriensis and Satyrium crassicaule. Another unexpected feature of this zone are prostrate climbers such as Secamone recemosa and Urera trinervis and obligate epiphytes like Begonia ampla and the endemic Impatiens letouzeyi (Balsaminaceae). There are several other clearly defined zones culminating in a belt of lake margin species with Cynorkis anacamptoides, Eulophia horsfallii, Floscopa glomerata, Habenaria procera, Polygonum setosulum, Rhynchospora corymbosa, Schoenoplectus mucronatus and the endemic fern Athyrium ammifolium (Woodsiaceae).


Brenan, J. P. M. 1978. Some aspects of the phytogeography of tropical Africa. Annals of the Missouri Botanical Garden, 65: 437-474.

Cheek, M., Onana, J. M., Pollard, B. J., Darbyshire, I. & Csiba, L. 2000. The Plants of Mount Oku and the Ijim Ridge, Cameroon. A Conservation Checklist. Royal Botanic Gardens, Kew.

Cheek, M., Pollard, B. J., Darbyshire, I., Onana, J. M. & Wild, C. 2004. The Plants of Kupe, Mwanenguba and the Bakossi Mountains, Cameroon. A Conservation Checklist. Royal Botanic Gardens, Kew.

Keat, R. W. J. 1955. Montane vegetation and flora in the British Cameroons. Proceedings of the Linnean Society of London, 165: 140-143.

Morton, J. K. 1986. Montane Vegetation. In: Plant Ecology in West Africa. Ed. G. W. Lawson. John Wiley & Sons Ltd.

Owiunji, I., Nkuuta, D., Kujirakwinja, D. Liengola, I., Plumptre, A., Nsanzurwimo, A., Fawcett, K., Gray. M. & McNeilage. A. (undated). The Biodiversity of the Virunga Volcanoes. Wildlife Conservation Society, Institute of Tropical Forest Conservation, International Gorilla Conservation Programme and others.

White, F. 1983. The Vegetation of Africa. UNESCO.