Drivers and pedestrians crossing overpasses and footbridges in Guangzhou in November could expect to see Bougainvillea glabra in full bloom against the backdrop of an azure autumn sky.

The flowers, which can range in color from purple, red and pink to white and yellow, cover the sides of 353 overpasses and footbridges measuring 330 kilometers in length in Guangzhou, bringing a riot of color to the cityscape.

Thirteen species have been selected out of a total of 150 to decorate the bridges together with some other plants. Careful management, means there are flowers in bloom all year round, up from two seasons in 2003 when the work began to beautify the bridges, said Ruan Lin, dean of the Guangzhou Institute of Forestry and Landscape Architecture.

As well as looking attractive, the flowers also bring marked ecological benefits in terms of improvements to air quality and mitigation of urban heat island effect－where a metropolitan area is warmer than surrounding rural areas due to human activity.

Guangzhou has applied for a national habitat award for the project after winning the Guangdong provincial award last year, Ruan said, adding that the city's experts have helped a number of other cities on the southeast coast garnish their bridges.

The floral bridges are only part of authorities' efforts to enable the city live up to its nickname of the "city of flowers".

Last year, the city's forestry and gardening administration implemented a five-year floral landscape plan, Ruan said.

Through careful selection and placement of species and thanks to the warm climate, significant blooms are available year round. Kapok, peach blossom and pink Bauhinia adorn the city in spring; Delonix regia, or flame tree, and Lagerstroemia indica, also known as crepe myrtle, in summer; Ceiba speciosa, or silk floss tree, and red Bauhinia in autumn; and plum blossom in winter. Flower sightseeing tips are posted on the administration's website to allow residents to appreciate the displays.

Floral spots across the city have been upgraded since last year to show more aesthetic sense and efforts are being made to promote the love of flowers in Cantonese culture through activities such as floral exhibitions, promotion of floral science and support for the decoration of residents' balconies.

In September last year, as a highlight of the city's floral affairs, the Guangzhou International Floral Art Exhibition was held along with the annual conference of the World Flower Council in Guangzhou.

Floral artists from more than 32 countries and regions participated in the events, and over 400 international flower art works were displayed in the city.

In addition, experts from Guangzhou led a team with members from across the country in formulating a national standard on floral decoration along overpasses and footbridges, which has been approved, Ruan said.