Plants fan-shaped to irregular in outline but rarely more than 2 cm wide; roots simple. Leaves more or less triangular, red to green and with translucent margins. Sporocarps spherical and mucilaginous.

Often seen as a red scum on the surface of ponds and rivers where the water in slow or still; occasionally cultivated but undesirable as it can spread rapidly in natural water bodies.

Will tolerate cool conditions.

Australia, NZ, America.

 

Azolla pinnata R. Br., Green Azolla (Ferny Azolla) from Asia, Africa, New Guinea, New Zealand and Australia has feathery rootlets and is found in similar situations, it is often red-brown and rarely used in cultivation.

Source: Spencer, R. (1995). Azollaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 1, Ferns, conifers & their allies. The identification of garden and cultivated plants. University of New South Wales Press.