Few visitors to the Xishuangbanna Dai Autonomous Prefecture in southwest China's Yunnan Province miss the chance to visit the Menglun Botanic Garden.

The Botanic Garden, also the seat of the Yunnan Tropical Plants Institute, is located within Mengla County, 96 km from Jinghong, capital of the prefecture. The Luosuo River, a tributary of the Lancan River, bends here, encircling the land into a calabash-shaped promontory, where the Botanic Garden is situated.

The promontory, 570 meters above the sea level, covers an area of 1,000 hectares with fertile soil. The average annual temperature is between 21 and 22 centigrade and the highest temperature is between 38 and 40 centigrade. Such a climate provides excellent conditions for tropical plants.

The Yunnan Tropical Plants Institute was established in 1958 under the initiative of Prof Cai Xitao, a well-known Chinese Botanist. It was first based in Menglong and was moved to the calabash promontory in 1959. With the development over the past four decades, it is now home to more than 3,000 domestic and foreign tropical and subtropical plants.

Within the garden, which belongs to the Chinese Academy of Sciences, visitors can enjoy various unique and rare plants. The dragon dracaena (Dracaena draco) with big leaves was cultivated by Prof Cai himself. The tree is the main ingredient for a herbal drug called dragon's blood, which can effectively invigorate the circulation of blood and stop bleeding.

Also worth mentioning is the upas tree (Antiaris toxicaria). It is extremely poisonous. When going hunting, the local people used to mix the juice from an upas tree and other toxicants and coat the arrow head with the mixture. The wild animal hit would die in seconds.

Another interesting plant is called dancing grass. Each of its stalks has three leaves: one long leaf and two short leaves. Each morning, the long leave would stretch out from the drooping stamen and the short leaves would move up and down as if a girl was dancing. They also dance to the rhythm of singing or music. At present there is no scientific explanation as to why the plant can dance. One suggestion is that the plant's autonomic nerve is extremely sensitive, therefore, it would move under the stimulus of sunlight or sound.

There are also fragrant bamboo, which the Tai ethnic people use to make delicious rice, talipot palm (Corypha umbraculifera) whose leaves were used for writing by the Tai people, ylang-ylang (Cananga odorate), the most precious perfume in the world.

(Chen Qiuping 1999.7)