asplenium ruta-muraria

Asplenium ruta-muraria is a species of fern commonly known as wall-rue (but which, as a fern, is not by any means closely related to common rue). In Germany, it is known as Mauerraute or Mauerstreifenfarn. It is a very small epipetric species, growing exclusively on limestone and other calcareous rocks. Its fronds are bluish-green and are heavily sub-divided, becoming up to 12cm in length.

Asplenium ruta-muraria is native to Europe, East Asia, and eastern North America. In North America, its range ...