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.

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