What is "thelypteris"

Thelypteris (maiden ferns) is a genus of ferns in the family Thelypteridaceae, order Polypodiales. If the genus is defined fairly broadly, it contains 875 species, many of which are extremely similar to one another, and is found nearly worldwide. The ferns are terrestrial, with the exception of a few which are lithophytes (grow on rocks). The bulk of the species are tropical, although there are a number of temperate species.

The genus name is from Greek thēlys "female" and pteris "fern". However, "female fern" usually refers to the common lady-fern.