Spore Morphology of Loxogramme (Blume) C. Presl and Its Taxonomic Significance

Loxogramme (Blume) C. Presl is a small genus and the basal lineage of the derived fern family Polypodiaceae. In this study, new spore observations on Loxogramme were observed using scanning electron microscopy. The newly generated data were integrated and compared with previously reported evidence on this genus. Two main spore shapes, trilete and monolete, were found, with transitional types also observed in some species. In addition, two different ornamentation types were found in this genus, either rugate or vermiculate with or without globes. The two different spore types of Loxogramme are distinct within the family Polypodiaceae, and also are taxonomically useful in clarifying groups of this genus.