The Lythraceae or loosestrife family is a medium-sized family of 32 genera and about 600 species mainly located in the tropics but extending into some temperate regions. It takes its name from genus Lythrum, an epithet derived from the Greek lythron, "blood," alluding to the color of the flowers. The name loosestrife refers to an old belief that this herb could quell the unruliness or strife of oxen when yoked, and it apparently does have the affect of keeping flies and gnats away. It is a mostly herbaceous family with some shrubs and trees. The leaves are typically opposite, simple and entire, and the flowers range from being radially symmetric to zygomorphic and are usually brightly-colored with 4-6 petals and twice as many stamens as sepals. The family is closely related to the evening primroses and includes such species as pomegranates, the water chestnut, the dyeplant Henna, and the crepe myrtles.