Polypodium is a genus of ferns in the family Polypodiaceae, subfamily Polypodioideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). The genus is widely distributed throughout the world, with the highest species diversity in the tropics. The name is derived from Ancient Greek poly ("many") + podion, on account of the foot-like appearance of the rhizome and its branches. They are commonly called polypodies or rockcap ferns, but for many species unique vernacular names exist.