Azolla rubra, known commonly as red azolla and Pacific azolla, is a species of aquatic fern native to Australia and New Zealand.[1] In New Zealand, it is also known by its Māori names Maori: returetu, Maori: roturotu, Maori: kārearea and Maori: kārerarera.
Azolla rubra is found in Australia and New Zealand. Its range is thought to extend to Papua New Guinea, Indonesia and Japan.[2] [3]
In New Zealand, it is found on the North and South Islands, and on Raoul Island in the Kermadecs.[4]
Forms extensive red mats on slow moving bodies of water such as streams, lakes, ponds and swamps. May also occur on man-made water bodies such as farm ponds, drains, ditches, dams and cattle troughs.