Bougainvillea arborea (Bougainvillea)

Bougainvillea arborea, commonly known as Tree Bougainvillea, is an evergreen to semi-deciduous shrub or small tree in the Nyctaginaceae family native to southeastern Brazil. Unlike the familiar sprawling and climbing Bougainvilleas, this species develops a more upright, tree-like habit and does not rely on surrounding vegetation for support. Mature plants may reach about 15 to 30 feet (4.5 to 9 m) tall, developing a rounded crown and woody trunk. The branches are generally less aggressively thorny than those of many commonly cultivated Bougainvilleas.

The true flowers are small, tubular, and creamy white, surrounded by showy papery bracts, typically in shades of lavender, violet, or purple. The flowers are notably fragrant, an unusual characteristic among Bougainvilleas, and bloom repeatedly in favorable warm conditions. Bougainvillea arborea grows best in full sun and well-drained soil and becomes drought tolerant once established; excessive watering or shade can reduce flowering. It responds well to pruning and can be maintained as a compact specimen or trained into a small ornamental tree. Hardy in USDA Zones 9b-11, it benefits from protection during freezes in marginal climates. Its naturally tree-like form, fragrant flowers, and abundant colorful bracts distinguish it from the more familiar climbing species and hybrids.