The Chinese call it the "Green Gem on the Crown of the Plant Kingdom", and it is the birthplace of conservation activities in Xishuangbanna. The garden was established in 1959 under the famous botanist Cai Xitao. In the garden's 860 ha. area, thousands upon thousands of varieties of tropical and subtropical plants from home and abroad are growing. Visitors can view many rare exotic and endangered plant species here; the dragon tree, the maytenwood, and the poisonous upas tree; the thirst-relieving "carriage-pole vine"; the " clock flower " that opens and closes along with the sunrise and sunset; the "dancing grass" that responds to sound; the "king lotus" which can support a seated child on the water; the "mystery fruit" able to turn sour to sweet, then sweet to sour; and the "King of Tea Trees", which authorities say is at least 800 years old; it continues to sprout, and give the flavour of its' homeland, the land of the Pu'er red tea .