Lythrum

Good adaptable plants, growing in saturated soil by the water's edge, under water, or in an ordinary border, but they do perform better when the soil doesn't dry out. These are herbaceous perennials, with opposite leaves and starry flowers in shades of white through to pink-purple. They are in the family Lythraceae, which includes only few genera grown in the UK, Punica, pomegranate, Cuphea, the cigar plant and Lagerstroemeria, crape myrtle.