Azollaceae
Leaves minute, up to 1.5 mm long. Whole plants 0.8–6 cm long. Rhizome with numerous roots, bearing leaves in two alternate rows Azollaceae
Roots feathery in mature plants, sometimes simple in young specimens. Plants regularly pinnate. Massulae of the microsporangia conical, with rounded bases; 1–6 weak, non-barbed, non-septate processes borne only on one side. Megasporangia each with 9 apical swimming floats. Coast and adjacent plateaus; Cumberland Plain. Floating on slow-moving or stagnant water Azolla pinnata
Roots simple. Plants irregularly pinnate. Massulae of the microsporangia spherical, with numerous barbed processes borne on all sides. Megasporangia each with 3 apical swimming floats. Widespread. Floating on slow-moving or stagnant water Azolla filiculoides