Athyrium (lady-fern) is a genus of about 180 species of terrestrial ferns, with a cosmopolitan distribution. It is placed in the family Athyriaceae, in the order Polypodiales.Its genus name is from Greek a- ('without') and Latinized Greek thureos ('shield'), describing its inconspicuous indusium (sorus' covering).The common name "lady fern" refers in particular to the common lady fern. Athyrium species are used as food plants by the larvae of some Lepidoptera species including Small Angle Shades and Sthenopis auratus.