Oncotheca is the sole genus of the Oncothecaceae, which is one of three families of flowering plants
endemic to
New Caledonia. Its placement has been enigmatic for a long time, but a recent phylogenetic analysis[5] based on 73 plastid genes found it to be sister to
Icacinaceae. It is now placed in the order
Icacinales.[6][7]
^Morat, P., and J. M. Veillon. (1988). Oncothecaceae. In Flore de La Nouvelle-Calédonie et Dépendances, edited by P. Morat and H. S. MacKee, 15:90–98. Paris: Muséum National d’Histoire Naturelle.
^Morat, P., T. Jaffré, F. Tronchet, J. Munzinger, Y. Pillon, J. M. Veillon, and M. Chalopin (2012). The taxonomic reference base Florical and characteristics of the native vascular flora of New Caledonia. Adansonia 34 (2): 179–221.
https://dx.doi.org/10.5252/a2012n2a1
^Stull, G. W., R. Duno de Stefano, D. E. Soltis, and P. S. Soltis. (2015). Resolving Basal Lamiid Phylogeny and the Circumscription of Icacinaceae with a Plastome-Scale Data Set.” American Journal of Botany 102 (11): 1794–1813. doi:10.3732/ajb.1500298.