Title: A key to the ferns of Pennsylvania. Includes a non-technical key for investigation of each of the fifty-nine species found in the state; directions for use of the key; an outline for aid in identification of ferns by sterile fronds alone; distribution of species through the state; and a list of ferns found in the vicinity of Johnstown, Cambria County.
Authors: Canan, Elsie Deane.
Publisher: Science Press]
Year: 1946
Subjects: Ferns Pennsylvania.