Greek helodes – of the marshes.

Submerged aquatic perennial herbs, generally with stolons. Leaves submerged, opposite or whorled, mostly linear, 1-nerved. Flowers unisexual, sometimes on the same plant, inconspicuous and held at the water surface; summer. Male flowers 1(3). Female flowers 1. Stamens 3-9.

Grown in ponds and aquaria.Widely naturalised worldwide and often confused with other genera especially Egeria.

12 species from America. 1 species naturalised in Australia.

Cuttings and stolons.

Flowers held at water surface; floral segments all of same size cf. Egeria.

Source: Spencer, R. (2005). Hydrocharitaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.