54 Giant sequoia Sequoiadendron giganteum
Also known as giant redwood or Sierra redwood or simply ‘Big tree’. These are the world’s largest single tree and have been measured at ninetyfive m in height and seventeen m diameter. The oldest known tree of this species is 3500 years. Mature trees can be free of branches to a height of 20-50 metres. It is well adapted to forest fires, the heat opening the cones. In fact forest fires are important for the reproduction of the trees. Fire suppression effort in their natural area of Sierra Nevada has resulted in reduced natural cycles and now controlled burns are used assist their health and reproduction.