Cystopteris fragilis (syn. C. dickieana)

This widespread little fern is of Scottish provenance where it is abundant and easily found in rock cracks and sundry centuries-old architectural features such as stone walls, stone bridges, stone follies and stone buildings that combine to make villages and gardens so damned picturesque especially when covered in ferns. The spores are covered by a bubble-like indusium which inspired the common name of Bladder Fern.