[3] A global phylogeny of Asplenium published in 2020 divided the genus into eleven clades,[4] which were given informal names pending further taxonomic study.

[5] The Pleurosorus clade has a worldwide distribution; members are generally small and occur on hillsides, often sheltering among rocks in exposed habitats.

[6] Within the subclade, the A. ruta-muraria aggregate (including A. dolomiticum) is sister to the species formerly segregated in the genus Pleurosorus.

[7] In North America, its range extends from western New England southwest along the Appalachian Mountains to Alabama and Tennessee.

It is also found in the Ozarks and in southern Indiana and Ohio, with outlying occurrences in Michigan, Ontario, Quebec, and Clinton County, Iowa.