Olea europaea is an evergreen tree which typically reach about 7-9m (25-30 feet) tall with a naturally slight weeping habit. When the trees are young, they have a smooth grey bark, but as they age the trunks become increasingly gnarly looking. The elliptical to lanceolate leaves are grey-green above and silvery beneath, up to 8cm (3 inch) long. To be able to survive in a hot and dry climate, the leaves have a protective coating and are hairy undersides, an adaptation that slows down the transpiration process. There are Olea europaea trees varieties grown for fruit harvest, for oil production and even fruitless varieties grown just for ornamental proposes.