About Icarus filiformis (A.Cunn.) Gasper & Salino
Icarus is a genus of ferns belonging to the family Blechnaceae, subfamily Blechnoideae. Per the 2016 Pteridophyte Phylogeny Group classification (PPG I), the genus contains only one species, Icarus filiformis. This genus is accepted in a 2016 classification of the family Blechnaceae, but other sources merge it into a very broadly defined genus Blechnum, which matches the entire scope of the PPG I subfamily Blechnoideae. Icarus filiformis has the synonym Blechnum filiforme, and is commonly called thread fern, or pānoko in Māori. It is endemic to New Zealand. This species grows with a creeping and climbing habit, and produces three distinct types of fronds: long climbing fronds with long pointed leaves, shorter creeping fronds with nearly round leaves, and fertile fronds with threadlike leaves — the latter feature gives the species its common name.
