Background This study aims to understand the idiosyncratic floral morphology in Dialypetalanthus and to compare it with the floral development in two other Condamineeae genera as well as in other Rubiaceae for which ontogenetic data are available. Material and methods Flowers in Dialypetalanthus develop a stamen-corolla-calyx tube, which can be considered as a floral morphological link between the genus and the other Rubiaceae. The polyandrous androecium originates from an annular intercalary meristem at the adaxial side of the stamen-corolla-calyx tube.