Herbs. Leaves basal or alternate, without stipules. Flowers usually in terminal racemes, regular, bisexual; bracts absent. Sepals 4, free, imbricate. Petals 4, clawed, often spreading in the form of a cross, rarely absent. Stamens usually 6, sometimes only 4; the 4 inner longer than the outer pair. Ovary superior, usually divided into 2 loculi by a membranous septum connecting the 2 parietal placentas. Ovules 2–many; stigmas sessile or almost so. Fruit a 2-locular capsule, either long ( siliqua ) or short ( silicula ), opening from the base by 2 valves; or the fruit separating transversely into 2 or more 1-seeded articles. A siliqua may be beaked, i.e., with a distinct sterile region above the valves. Seeds without endosperm; embryo curved; the radicle either bent along the edges of the 2 cotyledons ( accumbent ) or the radicle lying against the back of one of the cotyledons ( incumbent ) or folded so that they almost surround the radicle ( conduplicate ). 350 gen., mainly N. hemisphere, mostly cooler regions.Hesperis matronalis L. (Damask Violet, Sweet Rocket) has been recorded as naturalizing in the Jenolan Caves area