The genus was described by Richard Schomburgk (1848) with one species in a very brief, in his opinion unofficial or informal, but nevertheless valid description. A more ample description with an excellent plate was given by Progel (1868). Bentham & Hooker (1876) therefore regarded Progel as the true author of the genus and the species. Four species were described afterwards, one of which, B. cinchonioides, is here reduced to a synonym.