Studies of Tropical American Ferns. United States National Herbarium, 17:541+.

Pteridophyta (excepting Equisitaceæ and Isoetaceæ) of the northern United States, Canada and the British Possessions. In Britton and Brown, Illustrated Flora, etc., ed. 2, pp. 1-54. 1913. New York.

MEEHAN, THOMAS. Native Flowers and Ferns of the United States. Boston, 1878-9.

MOORE, THOMAS. Nature-printed British Ferns. 2 vols. London, 1859.

PARSONS, FRANCES T. How to Know the Ferns. Charles Scribner's Sons. New York, 1899.

PRATT, ANNE. The Ferns of Great Britain and Their Allies. F. Warne & Co. London. No date.

REDFIELD, JOHN. Geographical Distribution of the Ferns of North America. Torrey Bulletin, VI, 1-7. (1875).

RHODORA. Journal of the New England Botanical Club. January, 1899, to date.

ROBINSON, JOHN. Ferns in Their Homes and Ours. S.E. Cassino. Salem, 1878. Out of print.

SACHS, JULIUS. Text Book of Botany. (Translated.) Macmillan & Co. London. 8vo.