XVI International Botanical Congess

Fossil members of Marattia (Marattiales) are widespread and well recorded during the Mesozoic. As a characterized species in the Triassic-Jurassic of Asia, M. asiatica (Kawasaki) Harris has been described for nearly a century, however, the fertile structure of it is still unknown. Recent study on the compression specimens of M. asiatica using LM and SEM from the Lower Jurassic in Hubei, south China, reveal for the first time the internal structures of synangia and in situ spores. The linear synangia of M. asiatica are bivalved and attached on the secondary veins at the pinna margin. A synangium is composed of two long strips of laterally joined and triangular sporangia. Each sporangium contains a large number of monolete spores with granular exine and smaller size, resembling the dispersed genus Marattisporites. Morphological and structural features of synangia and in situ spores are compared with the related fossil and extant members of Marattia, so as to indicate their evolutionary significance.