A member of the orchid family, Ladies' slipper (Cypripedium pubescens), is native to North America. Called ladies' slipper because of the shape of its delicate flower, it is the roots and rhizomes of the plants that are used medicinally. Used as a nerve tonic, it has been used to produce a calming and cheering disposition, especially in children. It has been prescribed by herbalists in combination with other botanicals for insomnia, nervous irritability, menstrual irregularities, mental depression and childhood excitability. Ladies' slipper is not extremely common among current supplemental ingredients.