rock brake

(noun) any of several small lithophytic ferns of tropical and warm temperate regions. Synonyms: cliff brake, cliff-brake, rock brake.

(noun) dwarf deciduous lithophytic ferns. Synonyms: rock brake.

(noun) chiefly lithophytic or epiphytic fern of North America and east Asia. Synonyms: rock polypody, rock brake, American wall fern, Polypodium virgianum.