Water-cress - Nasturtium officinale

Short to medium, hairless plant, the stems thick and succulent, creeping and rooting, and sometimes floating. Leaves pinnate, deep glossy green, leaflets rounded or elliptical, usually unlobed. Flowers white, 4 to 6 mm in congested heads. Fruit, narrow, oblong 13 to 18 mm with two rows of seeds in each valve.

Nasturtium microphyllum and Apium nodiflorum (Fool's Watercress).

Fool's Water-cress has more pointed leaves and has umbelliferous flowers rather than the 4 petalled flowers of Water-cress.

Leaves, pinnate, hairless.  Seeds in 2 rows under each valve

General photo of plant in habitat, plus details of the fruits

Shallow, clear freshwater habitats. Rivers, streams, ditches and dykes.

May to October.

Perennial.

Fairly frequent in Britain except for Central and Northern Scotland.

Fairly frequent in Leicestershire and Rutland. In the 1979 Flora survey of Leicestershire it was found in 91 of the 617 tetrads.

In the current Checklist (Jeeves, 2011) it is listed as Native, occasional