Stratiotes aloides

Stratiotes aloides has a rosette of serrated leaves, lanceolate, up to 30 cm long in tufts. White flowers up to 45 mm across, with many stamens in the male plants, are produced in the summer.^[5]

In the summer this plant floats on the water surface with the leaves just above the surface. In the autumn they become covered with a slimy secretion (calcium carbonate) and the whole plant sinks to the bottom to rise again in the spring.^[6] Fossils have been found of this plant.^{[citation needed]}

Plants are dioecious. Male and female plants must be grown if seed is required. Only the female plant occurs naturally in Britain, though plants with hermaphrodite flowers are also found occasionally. Seed is never set in Britain, the plants increasing mainly by offsets.^[7]

In Ireland, it is found in shallow waters where it was introduced.^[5] Apparently now extinct in the north-east of Ireland.^[8] Rare in east England.^[9]

Most suitable for the cool aquarium or pond.^{[citation needed]}

Propagation from runners which form from the centre of the rosette of leaves.^{[citation needed]}

The herb has had a high reputation for treating wounds, especially when these are made by an iron implement. It is applied externally. The plant is also said to be of use in the treatment of ergotism and also of bruised kidneys.^[11]