A perennial that thrives in cold water and begins its life cycle in early spring. It is connected to a creeping rootstock. The hollow branching stern, 1-2 feet long, extends, with its leaves, above the water. The smooth, dark green, mustard-flavored leaves are odd-pinnate with 1-4 pairs of small, oblong or roundish leaflets. Small white flowers bloom in elongating terminal racemes. The fruit is a long, curved, linear-cylindric, partitioned pod. Naturalized in the U.S.

The leaves, flowers, seeds are rich in Vit. A, C, D, E, calcium, iodine and other trace minerals when harvested before the blossoms appear. These parts can be used raw, in teas, as a potherb or dried to flavor food for a peppery taste. Underwater parts or roots are tough and unpalatable. It is a antiscorbutic, diuretic, expectorant tonic, purgative, and stimulant. The leaves, roots, and young shoots are used for anemia, prevention of scurvy, goiters, heart trouble, blood cleanser, clears skin, for colds, sinus problems, respiratory and internal tumors, Best used when in flower. CAUTION: prolonged use, longer than 4 weeks, can lead to kidney problems. Do not harvest in polluted or stagnant water. Poisoning may occur if plant has absorbed heavy metals, toxins or have liver flukes.