Polypodiineae

The Polypodiineae is a suborder of ferns within the order Polypodiales. This group, also known as polypodiaceous ferns, is characterized by certain evolutionarily advanced features, including long-stalked spore-producing structures called sporangia. These sporangia have an incomplete, vertically arranged band of thick-walled cells. Members of this suborder are typically tropical or subtropical epiphytes, meaning they grow on other plants rather than in soil. They possess a root-like, creeping stem called a rhizome, which is covered in scales. The undersides of their leaves bear clusters of sporangia (sori) that usually lack the protective covering found in many other fern families.1

The suborder Polypodiineae encompasses several families, including Davalliaceae (rabbit's-foot fern), Dryopteridaceae (log fern, shield fern), Lomariopsidaceae, Nephrolepidaceae (sword ferns), Oleandraceae, and Polypodiaceae (polypodies). The classification and number of genera and species within these families are still subjects of study. Economically, these ferns are of minor importance, with a few exceptions grown as ornamentals, such as staghorn ferns.21