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Plant of the month May

Common Name: Hong Kong Orchid Tree

Scientific Name: Bauhinia x blakeana 

Family: Fabaceae - Caesalpinioideae




Bauhinia – for brothers, Gaspard and Jean Bauhin, 17th century Swiss German botanists.


blakeana – for Sir Henry Blake, Governor of Hong Kong 1898 - 1903.


A change hybrid, discovered from a single lovation - at Pokfulam on the western shore of Hong Kong.

Native Habitat

Only known from cultivation.


A medium sized tree, around 9 m tall with a spread ofi 4.5 m. Leaves are 7 to 10 cm long and 10 -13 cm wide, with a deep cleft dividing the apex. They are double-lobed and shaped like the wings of a butterfly. In Hong Kong, the leaf is known as the “Clever Leaf” and is regarded as a symbol of wisdom.


Although the flowers superficially resemble those of orchids, they are botanically more closely related to peas and beans of the Fabaceae family. Flowers are large (15cm across), showy, deep pink, fragrant and with 5-6 stamens (distinguishing it from similar-looking Bauhinia purpurea which has 3-4 stamens). Flowering occurs between March and July in Sydney.


Plants are sterile and thus do not produce fruit, even when flowers are deliberately pollinated.

Location in Garden

Tropical Garden facing the Band Lawn.


The first Hong Kong Orchid Tree was found around 1880 by Jean-Marie Delavay, a French Catholic missionary, near a
ruined building at Pokfulam, Hong Kong. He saw the beautiful pink flowers and took a cutting, which he propagated and grew at the sanatorium run by the missionaries in Hong Kong. Some time later, a cutting from this tree, was grown at the Hong Kong Zoological and Botanical Gardens and described botanically in 1908. Following 1914, this botanical garden starting distributing cuttings of the tree. It is thought more than 25,000 cuttings have been distributed world wide. They are all clones (genetically identical) to that first tree discovered in 1880. Although suspected earlier, it was not until 2005 that scientists were able to conclude that this tree was a hybrid of two other Bauhinia species, Bauhinia variegata and Bauhinia purpurea. This hybrid is sterile, and does not produce viable seed, meaning this variety of tree only exists because of human intervention through vegetative propagation. Since 1997, the flower has appeared on the Hong Kong coat of arms, its flag and coins. A statue of the flower was erected in Golden Bauhinia square, Hong Kong.

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