Blechnum L. >
Coenosori in a continuous or almost continuous line on each side of the midrib covering the vascular commissures, having a membranous indusium opening inwards towards the costa. Veins of the sterile fronds free Blechnum
Fertile and sterile fronds similar; the fertile pinnae or frond-segments slightly narrower to one-third of the width of the sterile
Sterile frond-segments (pinnae) very shortly and distinctly stalked in the greater part of the frond or in the lower third
Pinnae not articulated to the main rhachis. Rhizome shortly creeping or long-creeping. Spores with an alate, either reticulate or tuberculate perispore. Pendulous plants up to 120 cm long
Fertile pinnae c. one third to a half of the width of the sterile pinnae. Rhizome with non-fleshy, circinnate buds. Scales of the rhizome light fawn or brown or ferruginous, sometimes slightly darker towards the centre when old, dull to slightly glossy, narrowly lanceolate to narrowly ovate. Spores with a reticulate perispore, 49–75µm X 44-56µm; the wings 3.75–11µm diam, surrounding the spore. Pinnae light to medium green, dull, slightly auriculate at the base. Widespread. Common. RF and tall open forests. Ss, usually on rock ledges under caves or near waterfalls or on wet cliff-faces Blechnum ambiguum