Perhaps, South Bioko populations are in a basal position on the ML/BI/Beast trees because the plastomes provide a skewed view of the biogeographic history of L. columnaris , or there is sampling error because we sequenced only 1-2 individuals per populations. Furthermore, we do not have population data from Nigeria, and we did not find more populations in Cameroon, possibly for the local extinction of populations caused by the intense human transformation of Afromontane habitat on the sky islands.