British traders became the dominant European presence in the region by the mid-19th century, and the Crown used them to enforce abolition of the slave trade in the Gulf of Guinea.
Sites where B. bifarium specimens have been collected include: along the Douala to Bimbia road; Mfongu near Bagangu; Bana-Bateha near Fibé; Nkokom Massif near Ndom; Nyasoso on Mount Kupe; Kodmin in the Bakossi Mountains; and on Mount Cameroon.
In 1788, a British trader bought 30 persons held in pawnship in Bimbia, in present-day Cameroon, for transport to the Americas.
The Bimbia mission station and school, the first in mainland Cameroons, was founded in 1844/5 by the Fuller and Merrick families, and was quickly followed by a second at Duala founded by Alfred Saker and his family with the Sierra Leonian Thomas Horton Johnson.