Growing from sandstone outcrop in rich, mesic deciduous forest. ID based on rock substrate, smaller stature and largest leaves less than 8mm in length and widest at the base.
Common limestone-fern, will usually accompany A. trichomanes (ssp. quadrivalens) and A. viride.
Wall-Rue fern (Asplenium ruta-muraria), growing on dolomite cliff, Flowerpot Island, Georgian Bay, Tobermory, May 21/18
Wall-Rue fern (Asplenium ruta-muraria), dolomite cliff, Niagara Escarpment, Cup and Saucer Trail, Manitoulin Island, May 23/18
Wall-Rue fern (Asplenium ruta-muraria), dolomite cliff, Niagara Escarpment, Cup and Saucer Trail, Manitoulin Island, May 23/18