Teratologies in Nageia fleuryi (Podocarpaceae) suggest a pseudanthial origin of podocarpaceous pollen cones

Abstract

Wild-type pollen cones in Podocarpaceae are simple and “flower”-like, consisting of numerous non-axillary, hyposporangiate microsporangiophores. Teratological pollen cones of Nageia fleuryi are investigated here. One of the most striking and frequent forms is a compound “inflorescence”-like structure, consisting of numerous lateral pollen cones, here analogised with flowers. Each lateral pollen cone is inserted in the axil of a subtending leaf (pherophyll) and consists of several hyposporangiate microsporangiophores. Thus, the branching pattern in the teratological pollen cones corresponds strictly to the general branching pattern of seed plants. In the context of abnormal microsporangiophores that were previously documented for other coniferous groups, and the evolutionary transition series previously suggested for male reproductive structures in Taxaceae s.l., it seems highly likely that the simple, “flower”-like pollen cones of today´s podocarps are derived from a compound “inflorescence”-like ancestral condition by a simple reduction of lateral pollen cones (flowers) to just a single hyposporangiate microsporangiophore and the loss of all pherophylls within the pollen cone.