In Corsica, about 2,500 plant species grow in the wild. This wide range of species is due to the diversity of climatic and geological conditions, and to the turbulent history of the island. Almost a quarter of the territory is covered with shrubs and bushes that remain green and flower all year long: the maquis. This Mediterranean plant formation from 0.50 to 7 m (2 to 23 ft) in height extends from the littoral to lands at 900 m (2,953 ft) altitude. Young, it consists of monospecific expanses such as rockrose. Aged, it is similar to a forest where the strawberry tree, heather and holm oak dominate.