Bauhinia purpurea aka Orchid Tree

Bauhinia purpurea is the purple orchid-tree, in the pea family. It grows as a tree or a large shrub. Its native range includes India, Nepal, Bhutan, Pakistan, and Sri Lanka. It also reaches Myanmar and Thailand. It grows in mixed forests, on slopes, and beside streams. People grow it across the tropics for its flowers. Useful Tropical Plants reports its 2011 status as Least Concern.

Sources give a range of sizes. Florida guidance gives a garden height and width of 30–35 feet [9.1–10.7 metres]. Other accounts give heights of 13–33 feet [4–10 metres]. One gives a spread of just 6.6 feet [2 metres]. It grows fast, with slim trunks and a broad crown. Branches curve outward and droop toward the ground. Without pruning, low branches can give it a bushy form. The green, round leaves have two lobes. Their palmate veins spread like fingers from one point. Leaves grow in an alternate pattern along brown twigs. Sources say it may keep or shed its leaves.

Florida trees bloom from September to November, before leaves fall. The flowers have a scent and narrow petals. These may be purple, pink, or lavender. Their shape recalls an orchid, though this is no orchid. Bees carry pollen between the flowers. Flat brown pods follow and may stay through winter. The dry pods reach 6–12 inches long. Its flowers make it useful as a specimen tree. It also serves as a shade tree. Sources list uses along streets and to restore land.

Grow it in full sun and soil that drains well. It copes with some shade, clay, sand, and loam. It accepts acid to mildly alkaline soil. It copes well with drought; dry soil helps it bloom. Florida guidance places it in USDA zones 9b–11. Severe frost can kill young leaves, though plants may regrow. Pruning helps build a strong frame and control drooping branches. Weak wood can break in storms. The tree may also lack potassium. Borers, caterpillars, and mites may affect it. Leaf spot and leaf scorch may affect it too. Other serious pest and disease problems are rare. Fallen leaves, flowers, and pods leave litter. Seedlings can spread freely. Florida guidance classes it as invasive.

People cook the leaves, flower buds, flowers, and young pods. They also pickle buds or add them to curries. Useful Tropical Plants lists no known hazards. But it gives no assurance of safety for pets. It records folk uses of roots, bark, and flowers as medicine. Bark supplies fibre, tannins, and dye. The plant also yields gum. People use its wood for tools, joinery, and fuel.