• FLORA Ontario - searchable database of all plants of Ontario - University of Guelph
• Ferns of the Bruce Trail - Sydenham Bruce Trail Club
• Ferns and Fern Allies of the North Woods - Earl J. S. Rook
• Study of Northern Virginia Ecology - Stratford Landing Elementary School - Cinnamon Fern page
• Environment Canada - Species at Risk - Hart's Tongue Fern
• Latin name synonym page
• Connecticut Botanical Society - Connecticut Ferns
• Ferns et al of New England - by Don Lubin
• Andy's Northern Ontario Wildflowers - Ferns, Allies and Liverworts

Other

• Botanical Art (Yahoo discussion group) - Cynthia Padilla, Botanical Artist/Naturalist Illustrator