Comparative Anatomy of Reproductive Structures in Cyclanthaceae (Pandanales)

Abstract

Premise of research. The Neotropical family Cyclanthaceae is one of five families of the order Pandanales, which includes some misfit taxa that are morphologically highly anomalous. In the taxonomically isolated genus Cyclanthus, which is sister to all other Cyclanthaceae, individual flowers are not readily distinguishable. Instead, flowers are replaced by discoidal rings that encircle the inflorescence. We compare features that are shared among misfit taxa.Methodology. We use scanning electron microscopy and light microscopy to describe the reproductive structures of both subfamilies of Cyclanthaceae, including Cyclanthus bipartitus (Cyclanthoideae) and several Carludovicoideae.Pivotal results. Our pollination observations on Carludovica palmata flowers contrast with some other reports, because we observed only small black bees of the Meliponini tribe visiting this species. The anomalous reproductive structures of Cyclanthus show some features in common with Carludovicoideae, especially the presence of l...