Plant Diversity And Medicinal Plant Survey And Conservation In The Cherangani Hills,Western Kenya

Cherangani Forest Reserve is the fourth highest mountain in Kenya and has rich plant diversity.The forest is one of the five major water towers in the country and constitutes an important water catchment area.It is located in Western Kenya,comprising of 12 forest blocks which have been gazetted,however,little attention has been paid to plant diversity in the area.The forest blocks entail conservation value and maintain cultural significance to the surrounding communities.The geographical landscape provides a uniquely wide topography,and a wide range of biological diversity comprising of different plant species,especially undisturbed indigenous forests.Between July 2015 and January 2019,the botanical team consisting of botanists from the National Museums of Kenya and Sino-Africa Joint Research Center(SAJOREC),held several explorations and botanical surveys in the Cherangani hills.General walk-over survey method and plotless landscape defined sampling methods for plant specimen collection and sight observation were used to aid the characterization of the vegetation.Ethnobotanical data were obtained through interviewing informants using semi-structured questionnaires and extracting information from journals and books.Descriptive statistical analysis was applied to describe the medicinal data.Standard taxonomic procedures were followed diligently,and standard references were used for plant identification.An annotated checklist of the vascular plants of the region has been obtained through intensive field investigations and matching of herbarium specimens.In total,1296 species,including 17 endemic species are documented,belonging to 130 families and 608 genera.The flora represents 18.50%,43.83% and 54.17% of the Kenyan species,genera and families,respectively.The habit,habitat and voucher specimens,as well as brief notes on the distribution of each taxon recorded are presented in the checklist.It is the first exhaustive inventory of the terrestrial vascular plants to be documented in the region.The top 10 species-rich families are Asteraceae(66 genera/165 species),Fabaceae(39/98),Labiatae(32/68),Orchidaceae(23/65),Rubiaceae(25/65),Poaceae(40/59),Cyperaceae(8/40),Apocynaceae(20/38),Acanthaceae(17/36)and Malvaceae(10/34).Overall,296 medicinal plant species from 80 families and 191 genera were identified to be used for the treatment of various diseases by three communities,(Luhya,Marakwet and Pokot)in the region.Asteraceae family was the most dominant,representing 10.7% of the total medicinal plant species recorded.Roots(35.9%)represented the most commonly used parts of the plant.The commonly used method of preparation was decoction(54.9%).This study is of great significance for the protection and utilization of plant species and medicinal plants in the Cherangani Forest Reserve.At the same time,the survey provides detailed and reliable first-hand data for the compilation and research of Flora of Kenya.