The floral anatomy of Victoria Schomb. (Nymphaeaceae)

The vasculature and development of the flower of Victoria Schomb. are described. The vasculature is basically similar to that found in other genera of the Nymphaeaceae sensu stricto (e.g. Nymphaea L. and Nuphar Sm.). The early development of the flower is similar to that of a hypogynous flower, but meristematic activity shifts from the apex to the periphery in the form of an intercalary ring meristem. The innermost appendicular organs, including the gynoecium, arise by differentiation of tissues formed by this intercalary ring meristem. Evidence is assembled from the mature vasculature and developmental studies: (a) to refute Troll's interpretation that receptacular strips of tissue occur between the carpels and that the outer ovary wall is totally receptacular; (b) to propose that the occurrence of epeltate carpels in Victoria, as correctly described by Troll, has been phylogenetically ‘read’ in the wrong direction; (c) to propose that the flower of Victoria has evolved by (1) the adnation and connation of the proximal portions of the appendicular organs which now envelop the syncarpous gynoecium and (2) the concomitant condensation from a primitive ranalian floral apex.