Comparative floral development in the core genera of the Myoporaceae Sensu Chinnock

The aim of this study was to characterize the genera based on comparative floral ontogeny using representative species of the core genera of the Myoporaceae, Eremophila, Myoporum and Bontia. There are some unifying floral features of the family, however a mosaic of ontogenetic characters defines the genera rather than a continuum of floral features. The two bilateral forms of Bontia and Eremophila are not homologous in origin. The basal condition of pseudoactinomorphy characterizes the genus Myoporum sp. R.Br. Bilateral symmetry is a condition that is characteristic of the largest genus Eremophila sp. R.Br.; the floral form varies from weakly bilabiate to strongly. A strongly bilateral and bilabiate corolla characterizes Bontia, a monotypic genus. The order of initiation of floral primordia for all three genera differs throughout development as does the sequence of enlargement. The ontogenies of the core genera differ at early ontogeny subsequently giving rise to diversified floral forms.