Azolla nilotica is a medium-sized floating fern, that naturally occurs in the Nile and in eastern and central Africa. It is assigned to the family Salviniaceae.
Azolla nilotica is a floating water-bound fern of up to 32 cm (13 in) long, with a long, horizontal, branched, hairy rhizome of up to 2 mm (0.079 in) thick. Side branches are alternately set. The hairy roots spring in bundles from the nodes. Each leaf consists of an elliptic to broadly ovate green upper lobe of up to 2 mm (0.079 in) long, ...