The Linaceae is a family of flowering plants, mostly herbaceous or rarely woody plants, sometimes large trees in the tropics. The simple entire leaves are almost always alternate, sometimes with stipules. The hermaphroditic, actinimorphic flowers are pentameric, or very rarely tetrameric (much more frequently so in the tropics). The family is cosmopolitan, with some 250 species. There are eight genera, the largest being Linum, the flaxes, with 180-200 species.