P.  Goldblatt, Rodriguez, A., Powell, M. P., Davies, T. J., Manning, J. C., van der Bank, M., and Savolainen, V., ?Iridaceae ?Out of Australasia?? Phylogeny, biogeography, and divergence time based on plastid DNA sequences?, Syst. Bot., vol. 33 (3), pp. 495 - 508, 2008.