Azolla rubra

"Azolla rubra," known commonly as red azolla and Pacific azolla is a species of fern native to Australia and New Zealand. In New Zealand, it may also be known by its Māori names , , and .
Distribution.
"Azolla rubra" is found in Australia and New Zealand. Its range is thought to extend to Papua New Guinea, Indonesia and Japan.
New Zealand.
Found on the North and South Islands of New Zealand, as well as Raoul Island in the Kermadecs.
Habitat.
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.