Polypodium vulgare

Also known as the 'Common Polypody' or 'Adder's Fern'. An evergreen fern with lance-shaped to oblong, pinnate, thin to leathery, dark green fronds. Unusually for ferns, Polypodium vulgare thrives in dry conditions and can sometimes colonise old trees. If left to spread, it makes attractive evergreen ground cover in dappled shade under trees, where the soil is often quite dry.