Flowers unisexual; perianth 4-merous Haloragaceae
Aquatic plants or growing on mud. Petals absent in female flowers Myriophyllum
All leaves alternate. Emergent leaves linear to lanceolate, sometimes pinnatisect, usually less than 10 mm long. Flowers solitary, ± sessile. Male petals cream, c. 2 mm long
Leaves pinnately divided into usually 5 linear segments. Mericarps sparsely papillose. Coast and adjacent plateaus, Cumberland Plain. Shallow water or on mud Myriophyllum gracilegracile
Leaves entire or shortly toothed. Mericarps densely papillose. Widespread. Usually in swamps but sometimes in still water Myriophyllum gracilelineare