Climbing plants are plants which climb up trees and other tall objects. Many of them are vines whose stems twine round trees and branches. There are quite a number of other methods of climbing. The climbing habit has evolved many times. In most cases the climbing plants were more diverse (had more species) than their non–climbing sister groups. It is a key innovation which has been very successful. Over 130 plant families include climbers. Vine species may represent more than 40% of species diversity in tropical forests.