Plant Ecology and Evolution 153 (3): 399–426, 2020 https://doi.org/10.5091/plecevo.2020.1609 REGULAR PAPER Revision of Eulophia (Orchidaceae) in Nigeria, Cameroon, Equatorial Guinea, Gabon, and the Republic of the Congo Emma Ortúñez1,2,*, Roberto Gamarra1,2, Sara Gestal1, Álvaro Hernando1 & Pablo Galán Cela3 1Departamento de Biología, Universidad Autónoma de Madrid, C/ Darwin 2, ES–28049 Madrid, Spain 2Centro de Investigación en Biodiversidad y Cambio Global (CBIC–UAM), Universidad Autónoma de Madrid, C/ Darwin 2, ES–28049 Madrid, Spain 3Departamento de Sistemas y Recursos Naturales, Universidad Politécnica de Madrid, ES–28040 Madrid, Spain *Corresponding author:
[email protected] Background and aims – The genus Eulophia (Orchidaceae) is revised for Nigeria, Cameroon, Equatorial Guinea, Gabon, and the Republic of the Congo. The aims are: to present a morphological characterization of the main vegetative and reproductive features of Eulophia to clarify the delimitation of the taxa within the genus in the studied countries; to provide an updated identification key and an updated checklist of the genus with nomenclatural data, distribution maps, ecological information, and preliminary conservation status. This revision may serve as a basis for future studies of the genus in other regions of Africa. Material and methods – Relevant material kept in BM, BR, FHI, HBG, K, MA, P, and WAG was examined, using standard practices of herbarium taxonomy. Vegetative and reproductive structures were analysed. MapMaker was used to produce the distribution maps. Key results – A total of 24 species are recognised in the study area. The variability of perennating organs, leaves, sepals and petals, lip (including ornamentation), spur, and anther cap are described and depicted, and were found to be informative for species recognition.