1. The University of Yaoundé IFaculty of ScienceDepartment of Plant BiologyLaboratory of Plant Systematics and Ecology P.O. Box 812 Yaoundé Cameroon
2. Naturalis Biodiversity Centre Darwinweg 2 2333 CR Leiden The Netherlands
3. The University of Yaounde IHigher Teachers’ Training CollegeDepartment of BiologyLaboratory of Plant Systematics and Ecology P.O. Box 047 Yaoundé Cameroon
4. DIADEIRD 911 avenue Agropolis 34394 Montpellier cedex 5 France