Submerged perennial herb attached by roots formed from the lower nodes but most of the plant often near the surface. Upper internodes shorter than the leaves. Leaves stalkless in whorls of 3-5, to 4 cm long and 2-5 mm wide, the margins minutely toothed. Flowers unisexual, generally male, axillary from the upper nodes in summer. Petals white.
An aquarium weed used for oxygenation. Grows naturally in still or slow moving water.
S America. Naturalised in WA, NT, Qld, NSW and Vic.
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.