Lythrum is a genus containing around 40 annual or perennial plants that have a wide distribution throughout the temperate world. A popular garden plant, a variety of cultivars and varieties from different species are available. Commonly known as Loosestrife, these plants often have square stems, slender-leaves and spikes of star-like flowers in shades of purple, pink and white. They flower in summer - often for several months. In cultivation they do best in a moist habitat, forming attractive clumps of lance-shaped leaves. Plant near water, with other plants that enjoy moist soil. They are happy in full sun or partial shade. Many species and cultivars self-seed generously though, so deadhead old flowers regularly if not required to spread.