Although the distribution of B. porphyrostachys is widespread; from Southern Nigeria (in Okuma, Sapoba and Usonigbe Forest Reserves, and in Calabar) to Cameroon (specifically on Mount Cameroon) and Congo-Brazzaville; it is found only sporadically, as either an epiphyte, or a lithophyte (on lava rock).
Its varieties can be found in wildly varying habitats as an epiphyte (on branches of rainforest trees) or a lithophyte (on sandstone in open forest) in a continuous distribution along the east coast of Australia and in distinct populations along the Tropic of Capricorn.