Lythraceae is a family of flowering plants that includes 28 genera and about 620 species of herbs, shrubs, and trees. The larger genera include Cuphea (275 spp.), Lagerstroemia (56), Nesaea (50), Rotala (45), and Lythrum (35). It also includes the members of the former families of the pomegranate (Punica granatum, formerly in Punicaceae) and of the water caltrop (Trapa natans, formerly in Trapaceae). Lythraceae has a worldwide distribution, with most species in the tropics, but ranging into temperate climate regions as well.
The family is named after the type genus, Lythrum, the loosestrifes (e.g. Lythrum salicaria purple loosestrife) and also includes henna (Lawsonia inermis). It now includes the pomegranate, formerly classed in a separate family Punicaceae. The family also includes the widely cultivated crape myrtle trees. Botanically, the leaves are usually in pairs (opposite), and the flower petals emerge from the rim of the calyx tube. The petals often appear crumpled.
Characteristics
Lythraceae species are most often herbs, and less often shrubs or trees; the shrubs and trees often have flaky bark. Traits shared by species within the Lythraceae that distinguish them from belonging to other plant families are the petals being crumpled in the bud and the many-layered outer integument of the seed.
The leaves generally have an opposite arrangement, but sometimes are whorled or alternate. They are simple with smooth margins and pinnate venation. Stipules are typically reduced, appearing as a row of minute hairs, or absent.
The flowers are bisexual, radially or occasionally bilaterally symmetric, with a well-developed hypanthium. The flowers are most commonly quadimerous but can be heximerous, with four to eight sepals and petals. The sepals may be distinct, partially fused to form a tube, or touching without overlapping. The petals are crumpled in the bud and wrinkled at maturity, and are typically distinct and overlapping; they are occasionally absent....
