T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Azolla filiculoides (Azolla)

Kingdom: Plantae
Division: Pteridophyta
Class: Pteridopsida
Order: Salviniales
Family: Salviniaceae
Genus: Azolla
Species: A. filiculoides
Binominal name: Azolla filiculoides
Synonyms: Azolla filiculoides var. rubra, A. rubra, A. arbuscula,
A. magellanica, A. squamosa, A. caroliniana, A. japonica,
Common names: Azolla, Pacific azolla, Red azolla

Azolla filiculoides is a native aquatic free floating fern that forms extensive free floating mats on still water. Azolla is most common in shallow eutrophic (rich in mineral and organic nutrients) water bodies.
It has a very fast growth rate and is capable of spreading over lake surfaces to give complete coverage of the water in only a few months. Each individual plant is 1-2 cm across, green tinged pink, orange or red at the edges, branching freely, and breaking into smaller sections as it grows. It is not tolerant of cold temperatures, and in temperate regions it largely dies back in winter, surviving by means of submerged buds.
It is indigenous in New Zealand, Kermadec (Raoul Island), North and South Islands. It is also widespread throughout the Pacific extending into Asia and India.
In New Zealand it is not common in the northern regions of the North Island, the western South Island and in Central Otago.