A family of terrestrial ferns with scaly rhizomes, to which the fronds are not jointed. The sori are short, or joined together in a continuous line, on a vein parallel to the midrib of the pinna. The indusium is outside the sorus, attached to the leaf surface or margin. Spore-bearing fronds are often distinct from the vegetable ones. There are 10 genera, of cosmopolitan distribution, containing more than 260 species, of which 220 are in the genus Blechnum.
Subjects: Plant Sciences and Forestry.