An ethnobotanical survey was conducted in Tharaka-Nithi County in Kenya, which revealed high traditional knowledge of plant resources that were held by the residents. This is the first study to ever be conducted in all the regions of the county. 

214 plant species distributed in 73 plant families were recorded to have 616 use reports. This was documented from four communities with different but closely related dialects within a wide range of climatical and vegetation diversity. The major uses are shown in figure 2. 

Among the most important plant species based on the Relative Frequency of Citation (RFC) values were Zanthoxylum gilletii, Ludia mauritiana J.F. Gmel., and Carissa spinarum, which were reported to be used in management of malaria. Rauvolfia mannii Stapf, Ludia mauritania, Zanthoxylum gilleti and Ocotea usambarensis Engl. were reported to be applied against cough. Sclerocarya birrea (A.Rich.) Hochst. and Adansonia digitata L. were reported for backache and gastrointestinal conditions.  This study reveals the role of medicinal plant species in Tharaka-Nithi County. 

In light of most plant species recorded having their conservation status unknown, this is a great step towards achieving a sustainable future by ensuring that species use knowledge is spread to avoid overexploitation. The higher the number of species used for a need, the lower the risk of overexploitation.  

The research entitled “Traditional knowledge, use and conservation of plants by the communities of Tharaka-Nithi County, Kenya” was published in Plant Diversity. This work was supported by the National Natural Science Foundation of China and Sino-Africa Joint Research Center, CAS. Kenyan student Vivian Kathambi is the first author. Professor HU Guangwan  is the corresponding author. Several students from the group participated in the study.  

Fig. 1. Location and study sites of Tharaka-Nithi County, Kenya (Image by SAJOREC) 

Fig. 2. Number of plant species per use category in Tharaka-Nithi County  (Image by SAJOREC)