Icarus is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Icarus filiformis, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I).

[1] The genus is accepted in a 2016 classification of the family Blechnaceae,[3] but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.

[4] Icarus filiformis, synonym Blechnum filiforme,[2] is known as thread fern or pānoko in Māori.

It has three different types of fronds: long climbing fronds with long pointed leaves, shorter creeping fronds with nearly round leaves, and fertile fronds with threadlike leaves that give the species its common name.

This Polypodiales-related article is a stub.