Taxonomic and ecological study of the orchid flora of Ngong hills

Abstract

The Orchidaceae is one of the largest and most diverse families of the flowering plants, including 20,000 to 25,000 species distributed allover the world. The work presented here is the study of the taxonomy and ecology of the orchid Flora of the Ngong Hills. The hills lie on the edge of the Rift Valley, about 20 kilometers South West of Nairobi and they have been identified as an endangered ecosystem. The present study reveals that of the expected 21 species in 13 genera, only 17 species in 11 genera were recorded including 4 new records for the area. Keys for the determination of these species and a detailed morphological account of each genus and species is prepared. ' The ecological association of the orchid flora of the area is also discussed. Results also indicate that there has been extensive deforestation in the- area. Possible solutions and recommendations regarding its rehabilitation are suggested. The accumulated results have illustrated that orchids are extremely specialized environmentally and sensitive to slight variation, making them potential 'markers' for vegetation analysis.