About
Note: Do not rely on this information. It is very old.
Ceterach
Ceterach, a genus of ferns, of which one species, C. officinarum, once supposed to be efficacious in diseases of the spleen, is not uncommon on limestone rocks in England. Haying the sori on the under surface of the leaf hidden by thickly massed brown scales, it is known as the scale-fern.