Accepted name: Blechnum maximum
Rhizome forming a short trunk covered with black scales. Sterile and fertile fronds different. Fronds larger than other species, to 60 cm or more long and 15 cm wide. Blade lanceolate to ovate in outline. Stalk dark at the base. Sori close to the main vein with 1 row on each side, mostly 2-3 mm long.
Possibly a natural intergeneric hybrid between species of Doodia and Blechnum.
Needs shelter and warmth.
Large fronds with sori mostly 2-3 mm long (longer than in other species) in a single row each side of the midvein.
Source: (1995). Blechnaceae. In: . Horticultural Flora of South-eastern Australia. Volume 1, Ferns, conifers & their allies. The identification of garden and cultivated plants. University of New South Wales Press.