This is another fern that grows on the vertical rock face of the Niagara Escarpment, the smooth cliffbrake. But this one grows on the dry limestone out in the sun rather than on the shaded walls of a crevice. You can see clearly how it grows in a 'break' in the cliff - actually a pretty small crack.
In the picture below, the cliffbrake ferns are the two plants in the lower right of the picture, right on the rock face. I walked in to Old Baldy and climbed down below the cliff to get these pictures - right beside the rock climbers climbing up! It was a busy place today, with lots of people walking in to see the view with the beautiful fall colours, which are just nearing their best.
A closer view shows a reddish-brown wiry stem, and the few leaflets that make up a single leaf, the leaflets quite separated, unlike most ferns. It's only about 3 inches tall.
Looking at the underside of the leaflets, you can see how the sides curl in, and a line of brownish spore cases forms under the curl.