About Asplenium fontanum (L.) Bernh.
Asplenium fontanum (L.) Bernh. is a rhizomatous fern that produces fronds grouped in bundles, reaching up to 20 cm (8 in) in total length. Its rhizomes are covered in dark brown scales. Fronds grow on stems that can be as long as the leaf blades. The blades are pinnate, with eight to twenty toothed pinnules on each side, each pinnule reaching up to 4 cm (1.6 in) long. The longest pinnules are located in the middle section of the blade. The basal portion of the stem is brown, while the rest of the stem and the entire blade are bright green. On the underside of the pinnules, sori are arranged in groups of two or three.
This fern species is native to Western Europe, where it occurs primarily in the mountains of Spain, France, Italy, Switzerland and Austria. It is a rupicolous, or rock-dwelling, species that grows in cracks and fissures of limestone crags in cool, shady locations. It favors relatively high mountain areas, but can also grow at lower elevations on north-facing rocks or beneath rock overhangs. Its altitudinal range spans from 300 to 2,400 m (1,000 to 8,000 ft). It was reported growing in the British Isles during the nineteenth century, with records from Amersham churchyard, beside a waterfall in either Westmorland or Northumberland, and on the castle walls at Alnwick. This fern no longer grows in Britain.
