Are Berkheya and Valeriana both endemic to Africa?
Berkheya Berkheya is a genus of flowering plants in the aster family, Asteraceae, and the subfamily Carduoideae, the thistles. It is distributed in tropical Africa, especially in southern regions. Of about 75 species, 71 can be found in South Africa.
Brexia Brexia is a dense evergreen shrub or small tree of usually around 5  m high, with alternately set, simple, leathery leaves with a short leaf stem and lanceolate to inverted egg-shaped leaf blades. The pentamerous flowers occur in cymes. The petals are greenish white, the samens are alternating with wide, incised staminodes. The superior ovary develops in a long ribbed fruit. "Brexia" naturally grows on the coast of East Africa, on Madagascar, the Comoros and Seychelles. Opinions differ about the number of species in "Brexia". Sometimes the genus is regarded monotypic, "B. madagascariensis" being a species with a large variability, but other authors distinguish as many as twelve species. Common names for "B. madagascariensis" include jobiapototra, tsimiranjana, tsivavena, vahilava, voalava, voankatanana, voantalanina, voatalanina and votalanina (all Malagasy), and mfukufuku (Swahili), mfurugudu (Shambala, Tanzania) and bwa kato (Seychelles).