The Onagraceae are a family of flowering plants known as the willowherb family or evening primrose family. They include about 650 species of herbs, shrubs, and trees in 17 genera. The family is widespread, occurring on every continent from boreal to tropical regions. The family includes a number of popular garden plants, including evening primroses (Oenothera) and fuchsias (Fuchsia). Some, particularly the willowherbs (Epilobium), are common weeds in gardens and rapidly colonize disturbed habitats in the wild. One such species is fireweed (Chamaenerion angustifolium). The family is characterised by flowers with usually four sepals and petals in some genera, such as Fuchsia, the sepals are as brightly coloured as the petals.