10-20: see text Cystopteris is a genus of ferns in the family Cystopteridaceae.

This is a very diverse genus and within a species individuals can look quite different, especially in harsh environments where stress stunts their growth.

Their leaves are multiply pinnate, in that each leaflet is divided into smaller parts.

The sori are usually rounded and covered in an inflated bladder-like indusium.

Species include:[3][4] Cystopteris widely hybridizes internally.