This fern is considered rare and regionally significant in the Ottawa area. While walking through the older growth forest a puffball fungi on a rock caught my eye. I knelt down for a closer look and I then noticed this fern species growing on the same rock. I knew then that it was a spleenwort and something new for me (I've studied fern ID in books so I can recognize new species when I encounter them). I turned over the largest frond to check for sori, the arrangement of which can often help with identification, and accidentally broke what I discovered was a very brittle frond. Oops! I was being very gentle too! I then looked around for more specimens but found none, just the few fronds on this one rock. I now wonder if there may be some on a trail near the lime kiln where similar habitat exists. The last time I was there I found my first clump, a very small one, of Northern Maidenhair Fern outside of Gatineau Park where that species is common.