This fern is not common in the Ottawa area but can be found without much difficulty in the right habitat. I have not yet found any in Stony Swamp or anywhere else in the west Greenbelt, but in Gatineau Park, at Mer Bleue, and here at the Baxter Conservation Area it is not difficult to find. It is possible that I have overlooked this species, however, because the non-fertile fronds, fronds that don't have any fertile pinnae, are almost identical to the fronds of Cinnamon Fern, which is very common and widespread.
 
The fertile pinnae on this species occur in the middle of the frond and "interrupt" the non-fertile pinnae. In this photo the fertile pinnae are long spent leaving an "interruption" in the frond. I have always wanted to get a photo that showed the "interruption" well and this was the first photo I took that turned out okay. A very interesting and pretty species. I also recall reading that this fern species is a living fossil, being largely unchanged since it first appeared in the fossil record 200 million years ago.