From Wikipedia, the free encyclopedia.Phormium colensoi (syn. Phormium cookianum – but see below), also called mountain flax, or wharariki in Māori, is a perennial plant that is endemic to New Zealand. The greenish, yellow or orange flowers are followed by twisted seed pods. It is less common than the other Phormium species, P. tenax or harakeke. Mountain flax is also called whararipi, whatariki, mangaeka, kōrari tuauru (Williams 1971), wauraki (Bell 1890 sic.), coastal flax, hill flax and lesser New Zealand flax.