Cystopteris laurentiana (Weath.) Blasdell

Cystopteris laurentiana (Weath.) Blasdell. Cystopteris laurentiana, commonly called Laurentian bladderfern or St. Lawrence bladderfern, is a species of fern in the family Cystopteridaceae. It is native to eastern North America, primarily in the Great Lakes-St. Lawrence lowlands, but there are also scattered occurrences in New England and Atlantic Canada. It grows on cliffs composed of calcareous rocks, such as limestone, dolostone and diabase.