Scrophulariaceae: straggly, hairless perennial with creeping that root at the nodes, and upright flowering stems, reaching 30cm. found in shallow standing water and damp ground. The small blue flowers appear in pairs from May-September. The leaves are fleshy and short-stalked. Widespread and locally common throughout the Britain. Native to most Europe, Britain, from Norway south and east to North Africa, temperate Asia to Japan and Himalayas.
The leaves can be eaten raw or cooked. They can be added to salads, mixed with water cress or cooked with other strongly flavoured greens. A pungent flavour, although the leaves are wholesome they are not very palatable. Care should be taken if picking wild plants from dirty streams, ditches, and ponds as it can harbour the liver fluke parasite.
The whole plant has alterative, antiscorbutic, very mildly diuretic, emmenagogue and febrifuge properties. It is of little benefit as a medicinal herb, but has a beneficial laxative effect when included in the diet. The leaves are used in the treatment of scurvy, impurity of the blood. The plant is bruised and applied externally as a politic on burns, ulcers and whitlows.
Easily grown in a moderately fertile wet soil, growing best in water up to 15cm deep. Prefers cool summers and are happy in sun or shade. This is also a good bee plant. Sow seeds in autumn in a cold frame or greenhouse. When they are large enough to handle, prick the seedlings out into individual pots and plant them out in the summer. If you have sufficient, the seed can be sown in situ in the spring or the autumn.