Myriophyllum scabratum Michx. is treated as a synonym of the cut-leaf water-milfoil Myriophyllum pinnatum.12 The species ranges from southern Canada to Mexico.2 It inhabits mudflats, sloughs, ponds, lakes and swamp forests.13 Confusion with M. heterophyllum and M. hippuroides is common; fruits and mericarps provide the clearest distinguishing characters.3 The name M. scabratum is also wrongly applied to M. heterophyllum.4
Submersed, the plant bears comb-like pinnate, light to olive green leaves in whorls or alternately on green to dark red stems.13 As an aquarium plant it is mostly available under the name M. hippuroides.1 Cultivation in the aquarium is regarded as difficult; strong light and not too high temperatures are recommended.1 In a garden pond in summer, by contrast, it is easy to keep and occasionally flowers.1
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