Bauhinias belong to one of the world’s largest plant families, the Fabaceae or legume family, which has more than 18 000 species including important agricultural crops like Glycine max (Soybean), Pisum sativum (Pea) and Arachis hypogaea (Peanut). There are more than 200 different Bauhinias, distributed mainly across the tropics of Africa, Asia and the Americas, but the genus is also represented in southern Africa, where eight species occur. Bauhinia flowers occur in shades of pink, purple, magenta, mauve and white and, less frequently, yellow. The flowers have five petals, are often fragrant and produce long, woody seed pods. Each leaf has two identical lobes which resemble the open wings of a butterfly. The genus name Bauhinia honours the Swiss-French botanist brothers, Johan and Caspar Bauhin. One of the best-known Asian Bauhinias is the beautiful hybrid Bauhinia x blakeana, also known as the Hong Kong orchid tree, which originated in cultivation in Hong Kong in 1880 as a result of a cross between B. variegata and B. purpurea, and it is Hong Kong’s floral emblem. It has purplish-mauve blooms and is widely used in urban landscapes in Hong Kong, especially as a street tree. Ornamental Bauhinias are grown for their showy flowers and decorative leaves and seed pods. They are popular plants in temperate, subtropical and tropical gardens. They are useful as small to large shrubs, as trees and scramblers, as informal hedges and for screening. The more vigorous species perform well in large, landscaped beds and in traffic island and highway plantings, whereas the smaller-leafed species can be grown in rockeries and large containers. After flowering, their ornamental, woody seed pods remain attractive on the plants for several months. Bauhinias are long-lived, summer-growing plants and are best planted out in spring. They require slightly acid, well-drained, well-composted soils and full sun. Young plants need heavy drenching until they are well established. Mature specimens are fairly drought-resistant. Although they experience dry winters in their natural habitat, they are not adversely affected by heavy winter rainfall and, once established, can take light winter frost. Propagation is easy from seeds soaked overnight in warm water and sown in spring. Germination of fresh seeds occurs within 3-4 weeks. Their nectar is strongly attractive to butterflies, moths and other insects which, in turn, attract insectivorous birds to the garden, including Robins, Sunbirds and White-eyes.
This waterwise shrub or small tree is endemic to the coastal area of the Eastern Cape and KwaZulu-Natal from the Kei River to just south of Durban. It is found in valley bushveld vegetation. It was named for the South African naturalist Col. J.H. Bowker (1822-1900) who was co-author of the book South African Butterflies. Forming a small tree 5-6 m high, B. bowkeri flowers from early October to late December and becomes covered in clusters of large, sweet-scented, white flowers with wavy petal margins. These are followed by attractive, long, hanging seed pods that unfurl spirally and remain attractive on the stems for months. It is an excellent choice as a specimen tree for a medium-sized garden, for planting along fences and for screening unsightly walls, as a clipped hedge, planted in groups in large garden beds or as a quick-growing screen. It also has potential for office complex gardens and as a street tree. In ideal conditions it is a vigorous grower and may need annual pruning after flowering. The plants grow extremely well in granitic soils in the southern suburbs of Cape Town, requiring no summer watering once established.