This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Rhizome thick, tufted. Fronds tufted, simple, coriaceous. Sori on the veins, in opposite transverse lines at right angles to the midrib. Indusium linear, double. There are nine species, found in temperate and tropical regions. The old Greek name.
1. S. vulgare. Hart's-tongue Fern. - A common species in hedgerows and shady places, where the ligulate fronds vary from
6 inches to 2 feet or more in length. The varieties are very numerous, and many of them highly curious. This also has a very wide range of distribution.