Native to the subtropical regions of northwestern Argentina and southern Bolivia, this tree is now found across warm temperate zones worldwide and has naturalized in parts of Australia, South Africa, and the southern United States. It grows as a semi-deciduous tree reaching heights of 25 to 50 feet, with an irregular crown that often becomes rounded with age. Cultivated primarily for its springtime floral display, it produces terminal panicles of tubular flowers that measure around 2 inches long, with a flaring, five-lobed mouth and a color that ranges from lavender to blue-purple, often blooming in dense clusters before or during leaf flush. It flowers most reliably in areas with distinct dry seasons followed by rainfall, and in such climates, the floral display can be synchronous and dramatic, with blooms carpeting sidewalks and streets beneath. The tree has earned the Royal Horticultural Society’s Award of Garden Merit, recognizing its ornamental value. It is widely planted along boulevards and in public parks in cities such as Pretoria, Johannesburg, Brisbane, Los Angeles, and parts of Mexico. Invasive behavior has been documented in parts of Queensland, Australia, where it self-seeds and establishes in disturbed areas.
Cultivars include 'Alba', which bears white flowers, and 'Bonsai Blue', a dwarf form reaching only 10 to 12 feet. In Paraguay, it holds the status of national tree. Flowering can vary significantly by altitude and latitude, with trees in equatorial zones sometimes blooming twice annually. The floral tubes exhibit a faint, sweet fragrance detectable at close range, but not strong enough to fill an area. Petals are fused at the base, creating a trumpet shape, and the inner surfaces often display faint stripes or color gradations that serve as nectar guides for pollinators. In some regions, it is used for honey production due to its high nectar yield. It can survive brief dips into the low 20s Fahrenheit. Photographed in Boquete, Panama.