Oregano (Origanum vulgare) is a species of flowering plant in the mint family, Lamiaceae. It was native to the Mediterranean region, but widely naturalised elsewhere in the temperate Northern Hemisphere. A relative of the herb marjoram, oregano has purple, pink or white flowers and spade-shaped, olive-green leaves. It is a perennial, but it is grown as an annual in colder climates as it often does not survive the winter. Oregano leaves are widely used as a culinary herb, and its oil is often used as a dietary supplement, although there is no clinical evidence that it has any effect on human health. This photograph of an inflorescence of oregano was taken in Keila, Estonia; the petals of the flowers depicted are approximately 5 millimetres (0.20 inches) in length. This picture was focus-stacked from 66 separate images.Photograph credit: Ivar Leidus