Systematics Of The Genus Eulophia R. Br. (Orchidaceae) In Ghana

Abstract

The family Orchidaceae includes 850 genera and 24, 000 species, and it is arranged into 70 subtribes, 22 tribes, and five subfamilies on the basis of anther number and position. Many orchids are utilized in the traditional system of medication as medicines for several illnesses. There is no complete taxonomic revision of the genus Eulophia in Africa. A previous study based on morphological, ecological, and biogeographic characters of Eulophia cristata in Ghana has been reported by Lock and Profita (1975). However, the extent of morphological variations in species of the genus in Ghana has not been analyzed. The overall goal of this study is to undertake a systematic study of the genus Eulophia in Ghana for their sustainable utilization and conservation. 50 herbarium specimens of the genus Eulophia (35 specimens at GC, 10 specimens at CCG, and 5 specimens at KUU) were examined for morphological characters. Information from herbarium labels of the specimens examined were retrieved to understand aspects of the ecology such as phenology, habitat types and pollinator-flower relationship for the species of the genus Eulophia. Taxonomic studies focused on development of an authoritative checklist and construction of dichotomous keys for identification of species of the genus. Morphological studies on the species of Eulophia from Ghana suggested eight species but records from the herbaria in Ghana provided nine species. The members of the Eulophia range from small to large herbs, lacking woody stems; plant height ranges from 560–2000mm, 2– 16mm in width; has leaves that are often alternately arranged. Leaves are plicate, erect, often linear to lanceolate. Flowers are mostly in the shades of yellow and red, except shades of green in E. euglossa and E. flavopurpurea. Generally, the species of Eulophia have a cosmopolitan distribution across the country from the herbarium records.