Aquatic herb with stems to several feet long. Leaves 1-2 cm long, 2-4 mm wide in whorls of 3, occasionally the lower ones in pairs, linear to oblong, minutely toothed, blunt tipped. Flowers with sexes on separate plants; summer. Petals white to pale purple.
A common aquarium plant widely naturalised in Europe.
N America. In Australia naturalised in cold flowing or still water and a major weed of larger irrigation channels in WA, NSW, Vic and Tas.
Source: (2005). Hydrocharitaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.