Hong Kong's centrepiece at this year's International Horticultural Exposition will not be a tree or a plant but a tree-like architectural design combining wind, water, electricity and vegetation.

     The six-metre high Tree-ZE is composed of 360 mini-windmills which pump water from a pond at its base to the top of its pergola. The water then cascades down the plants coiling around the pergola back into the pond. The display will highlight the Hong Kong Garden at the expo, which will be held from April 28 to October 22 in Xian.

     A project of the Architectural Services Department, the Hong Kong Garden is 716 square metres in area, showcasing Hong Kong¡¯s vegetation and special geological features. Architects have imitated the shape of the hexagonal volcanic rock columns seen at the Hong Kong Geopark in the garden¡¯s floor tiles. The hexagonal tiles are made from recycled glass and cement, a Hong Kong innovation.

     The garden features plants from different geographical locations, including species like the Hong Kong orchid tree, dwarf red ixora, Chinese hibiscus, rhododendron, banana shrub and sweet osmanthus. Seventeen shrub species and six tree species from other Mainland provinces are also used in the garden. About 12 million visitors are expected to visit the exposition, an approved event of the International Association of Horticultural Producers.

The Guangyun Entrance, located at the north-east part of the exposition site, is the main entrance of the International Horticultural Exposition 2011 Xian, and it crosses the 60-meter wide Expo Avenue. The avenue can hold as many as 20,000 passengers during peak hours.