Blechnaceae

Terrestrial ferns. Rhizome mostly short and erect, sometimes with a short trunk up to 50 cm high, otherwise creeping or more rarely twining up trees, dictyostelic, clothed with non-peltate, non-clathrate, often black scales. Stipe not articulated to the rhizome, with several vascular bundles. Fronds usually pinnatifid or pinnate, sometimes simple or lobed, uniform or dimorphic; the fertile fronds often much narrower than the sterile ones. Veins free or anastomosing into a row or rarely several rows of areolae near the costae. Sori short and often later confluent, more usually elongated into linear coenosori which are borne on vascular commissures parallel to the costa. Indusium opening inwards towards the costules or costae, frequently linear or oblong, rarely absent. Sporangia large, with a longitudinally interrupted annulus which includes 14–28 thick-walled cells. Spores bilateral, monolete, with or without a perispore. 9 gen., cosmop., especially S. Hemisphere.