Lavender is the name given to several species of herbaceous, perennial shrubs in the genus Lavandula which are grown as ornamental plants or for essential oil. Lavender plants are small, branching and spreading shrubs with grey-green leaves and long flowering shoots. The leaves can be simple or pinnate measuring 30-50 mm (1-2 in) in length. Lavender is also grown for the production of its essential oil, which comes from the distillation of the flower spikes of certain lavender species. The oil has cosmetic uses, and it is believed to have some medicinal uses.