Parablechnum cordatum (synonyms Blechnum cordatum, Blechnum chilense),[1] the Chilean hard fern or costilla de vaca (Chilean Spanish for "cow's rib"), is a fern of the family Blechnaceae, native to Chile. It is also found in neighboring areas of Argentina and the Juan Fernández Islands.
It grows to 0.9–1.8 m (2 ft 11 in – 5 ft 11 in), often developing a trunk-like appearance over time. The fertile fronds are more erect, with narrower pinnae, than the infertile ones.[2]
This plant has gained the Royal Horticultural Society's Award of Garden Merit.[3]