Kingdom: Plantae
Division: Pteridophyta (Filicophyta)
Class: Pteridopsida (Filicopsida)
Subclass: Pteriditae
Order: Pteridales
Family: Pellaeaceae
Genus: Pellaea
This fern is usually found in the bleakest, most isolated limestone cliffs, often in small cracks under overhangs. It sometimes grows on other rocks. Cytological studies have demonstrated that this is not only a different species from P. atropurpurea, but that P. atropurpurea is of hybrid origin with P. glabella as one of the parents.
The smooth cliff brake is extremely difficult to cultivate.