[1][4][5] Meanwhile, in a 1975 Ph.D. thesis, Robert Faden treated Tricarpelema as a subgenus of the closely related genus Dictyospermum, while in 1980 R.S.

As the African species differs from the Asian taxa in a number of important morphological features as well as in habitat, Faden assigned it to a new subgenus Keatingia.

The genus can be found there from Bhutan and eastern India, west to Vietnam, southern China, and the Philippines, and south to Malaysia, Brunei, and Indonesia.

[1] Habitat information for most of the Asian species is poor, but most are known to be forest understory plants, often in moist situations.

The African species, T. africanum, on the other hand, is found in relatively dry areas, often in full sun.

Robert Faden suggests that T. africanum may have adapted to drier conditions from members of the genus once found in African rainforests which later died out in response to prehistoric aridification of Africa.