This plant family comprising about 2 800 species in 160 genera is distributed mainly in tropical and subtropical regions. Members of the Caesalpiniaceae are mostly evergreen or deciduous trees, shrubs or vines. The majority have pinnately compound leaves in alternate arrangement. Flowers are bisexual and bilaterally symmetrical. Fruits are legumes.

One of the major genera is Bauhinia. This garden grows 8 species including Hong Kong Orchid Tree (Bauhinia blakeana), Purple Camel's Foot (Bauhinia purpurea) and Camel's Foot Tree (Bauhinia variegata).

Hong Kong Orchid Tree (Bauhinia blakeana) was chosen as the city flower of Hong Kong in 1965. It flowers from November to March. As for the Purple Camel's Foot (Bauhinia purpurea) and Camel's Foot Tree (Bauhinia variegata), their flowering periods are from October to January and January to March respectively.