Polypodiidae

The subclass Polypodiidae, commonly known as leptosporangiate ferns, is a diverse group of ferns found worldwide, though they are most abundant in tropical and subtropical regions. These ferns typically have a horizontal stem called a rhizome, from which deeply divided leaves (fronds) and roots grow. A distinctive characteristic of their fronds is circinate vernation, where they uncurl as they develop.12

Polypodiidae ferns reproduce via spores produced in structures called sporangia, which are often clustered on the undersides of the fronds in groups called sori. These sori usually lack a protective covering, unlike in many other fern families. While most ferns are terrestrial or epiphytic (growing on other plants), some species have adapted to dry habitats, rocky environments, or even aquatic conditions. The family Polypodiaceae, within this subclass, includes about 1,200 species across 56 genera, with notable examples like staghorn ferns and true polypodies. Economically, their importance is mainly limited to ornamental uses.134