The tropical highlands of Africa, often referred to as an afroalpine ecosystem, exist along the Great Rift Valleys of East and Central Africa, which extend through Kenya, Tanzania, Uganda, Ethiopia, Burundi, and Rwanda. In recent geologic times, glaciers have persisted on Mt. Kenya, Mt. Kilimanjaro and Ruwenzori. Afroalpine vegetation begins at the elevation where the ericaceous belt (trees and shrubs) ends, ranging between 3550 and 4100 m (11,647 and 13,451 ft) and extending to the highest peaks within the mountain ranges, the highest of all peaks being Mt. Kilimanjaro at 5,895 m (19,341 ft). Several bryophytes and lichens are found in these areas, though few vascular plants persist due to the harsh environment.