An international team of specialists has conducted a study of 439 tea tree samples from 11 African and Asian countries and concluded that 79% of African tea trees are Indian Assam tea (Camellia sinensis var. assamica which has likely originated from India and/or Sri Lanka).
Only 4% of African samples were Chinese Assam tea (C. sinensis var. assamica of Chinese origin), and it is mostly grown in Kenya, while in other African countries there’s almost no such tea. In all African countries, a small, but noticeable fraction of the grown tea trees is C.sinensis var. sinensis brought from China, and in Madagascar this tea variety even dominates over Indian Assam tea.