Mentha aquatica - Hardy, herbaceous perennial. 60-90 cms height, 1 metre width. Full sun to part shade. Pale purple flowers in summer and autumn. Flowers attractive to bees and butterflies. Plant spreads by underground rhizomes, and can be invasive. Medicinal herd. Also known as Druids Mint, being one of their sacred herbs. Also an edible mint, but very strongly flavoured. Grows in most soil types, and will grow in heavy clay soil. Grows best in moist to wet soil. Its natural habitat is around ponds, streams, wet areas in meadows and woods, and along waterways. A good bog garden plant. Light pruning promotes new growth. An aromatic plant. Not frost tender. An excellent plant for animals, all grazing animals can eat it. It is an excellent herbal tonic and digestive aid for animals.