[1] In New Zealand, it is also known by its Māori names returetu, roturotu, kārearea and kārerarera.

[citation needed] Azolla rubra is found in Australia and New Zealand.

Its range is thought to extend to Papua New Guinea, Indonesia and Japan.

[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.