I had never really studied ferns until this summer, but they are actually a fascinating group. Also one that is surprisingly (to me) straightforward to identify. There are certainly still some tough identifications though. Hopefully I have everything in this post correct!
I've been using the Peterson guide to Ferns of Northeastern and Central North America. The guide published by the Owen Sound Field Naturalists is apparently also excellent although I've never used it.
Speaking of the Bruce Peninsula, it is one of the best places to find ferns due to the limestone rock and many cliffs. One specialty is the Northern Holly Fern (Polystichum lonchitis):
Maidenhair Spleenwort (Asplenium trichomanes) is another fern found on the Bruce. Like some other species, it is reasonably common along the Niagara Escarpment but hard to find elsewhere.
Moving up to Algonquin Park, the fern diversity is lower but still interesting. Oak Fern (Gymnocarpium drypoteris) is common in woods, including on shady rockfaces.
I showed the rare (for Ontario) Broad Beech Fern in my recent post about Rondeau. This is Narrow Beech Fern (Phegopteris connectilis), a common species in Algonquin.
The three species of Osmunda are large common ferns found in various wet habitats. This is Cinnamon Fern (O. cinnamomea), found in swamps and other very wet areas, generally with some shade.
The Wood Ferns (Dryopteris) are a large and complex group. While most are found in woods as you would expect, the distinctive ladder-like Crested Wood Fern (D. cristata) is found in wet areas. The books say that is usually found in swamps, but most I've seen have been in sedgy marshes.
Many species of fern are found in crevices of cliffs and rockfaces. Most require basic rock, but a few do use the acidic and nutrient-poor rock of Algonquin Park, including Rusty Woodsia (Woodsia ilvensis).
The Moonworts, Grape Ferns and Adder's Tongue Ferns form a group quite distinct from the typical ferns. This is a Grape Fern (Botychrium), but I'm not sure which species. There were quite a few of these odd ferns growing in a very dry, sunny area. The sterile and photosynthetic frond is on the right, while the fertile frond is on the left, covered in sporangia which will release miniscule spores.