About Asplenium ruta-muraria L.
Asplenium ruta-muraria L. is a fern species commonly called wall-rue. As a fern, it is not closely related to common rue. This is a very small epipetric species that grows exclusively on limestone and other calcareous rocks. Its fronds are bluish-green, heavily sub-divided, and can reach up to 12 cm (4.7 in) in length.
This species is native to Europe, East Asia, and eastern North America. In North America, its range stretches from western New England southwest along the Appalachian Mountains to Alabama and Tennessee. It also grows in the Ozarks, and in southern Indiana and Ohio, with isolated outlying occurrences in Michigan, Ontario, Quebec, and Clinton County, Iowa. In Europe, it is a common species that frequently invades masonry. In the United States, it is harder to find, and grows most often in pockets within very well-weathered, fairly dry limestone outcrops.
