Haloragaceae >
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 entire or shortly toothed. Mericarps densely papillose. Widespread. Usually in swamps but sometimes in still water Myriophyllum gracilelineare