Bauhinia is a large genus of flowering plants in the subfamily Cercidoideae and tribe Bauhinieae, in the large flowering plant family Fabaceae, with a pantropical distribution. The genus was named after the Bauhin brothers Gaspard and Johann, Swiss-French botanists. Many species are widely planted in the tropics as orchid trees, particularly in India, Sri Lanka, Vietnam, Nepal and southeastern China. Other common names include mountain ebony and kachnar. Before the family was reorganised, a number of genera including the lianas of genus Phanera were placed here (see related genera). In the United States, the trees grow in Hawaii, coastal California, Arizona, Texas, Louisiana, and Florida. There are native species, like Bauhinia lunarioides native to Texas and widely planted in the Southwest as a landscape plant. Parts of some species of bauhinia like B. purpurea and B. malabarica are used in Filipino cuisine (known collectively as alinbánban or alinbángbang, "butterfly"). Bauhinia × blakeana is the floral emblem of Hong Kong—a stylized orchid tree flower appears on the flag of Hong Kong and Hong Kong Airlines (formerly CR Airways) uses 'Bauhinia' as its radio callsign in air traffic communication.

Evolution

The oldest known species is B. tibetensis, known from fossil leaves from the Late Paleocene of the Tibetan Plateau, where it inhabited the Kohistan-Ladakh Arc, an island arc that existed in the region at the time. It has been suggested that the Asian clade of Bauhinia originated as early as the Early Paleocene, when it dispersed from the genus's region of origin in Africa.

Description

Bauhinia trees typically reach a height of 6–12 m and their branches spread 3–6 m outwards. The lobed leaves usually are 10–15 cm across. The five-petaled flowers are 7.5–12.5 cm diameter, generally in shades of red, pink, purple, orange, or yellow, and are often fragrant. The tree begins flowering in late winter and often continues to flower into early summer. Depending on the species, Bauhinia flowers are usually in magenta, mauve, pink or white hues with crimson highlights.

Cultivation

Propagation of Bauhinia species is from seeds or cuttings. They thrive in alkaline soils and do not tolerate salty conditions. Full sun exposure is preferred but they can be grown under partial sun. Generous watering is needed during summer; moderate moisture required in winter.

Species

Accepted species

Plants of the World Online currently (March 2023) includes the following species:

Hybrids

One hybrid is known:

Fossils

Several fossils of Bauhinia species have been discovered:

Segregated genera

Species in the genera Barklya, Gigasiphon, Lysiphyllum, Phanera (including Lasiobema), Piliostigma, Schnella, and Tylosema are sometimes included in Bauhinia sensu lato or considered as tribe Bauhinieae.