134551 WATERCRESS Rorippa nasturtium-aquaticum (Brassicaceae) Height to 15cm. Usually creeping perennial of shallow streams and ditches. FLOWERS are 4-6mm across with 4 white petals; in terminal heads (May-Oct). FRUITS are narrow pods, 16-18mm long, containing 2 rows of seeds. LEAVES are dark green and pinnately divided; persist through winter. STATUS-Widespread and common; widely cultivated in S England.