Greek: Blechnum is derived from the word blechnon, which is an ancient Greek word for ferns in general.
Rhizome: erect to creeping, scales brown or black.
Frond: evergreen, dimorphic, fertile leaves more erect and longer than sterile leaves.
vascular bundles: more than 2 vascular bundles arranged in arc.
Blade: pinnatifid to 1-pinnate, ovate, leathery, young fronds are often red.
veins sterile:free, often forked; fertile: veins of fertile leaves united to form sorus-bearing secondary vein parallel to costa or costule.
Sori: elongate, continuous, on both sides of the costae, indusium: flap-like, opening towards the costa.
Emerging fronds in the genus are usually red or reddish, loosing the color when fully expanded.
Blechnum spicant. a) free venation in sterile pinna; b) netted venation of fertile pinna.
Illustration from Scandinavian Ferns by Benjamin Ĝllgaard and Kirsten Tind, Rhodos, 1993.