Jacaranda is a genus of approximately 49 species of flowering plants in the family Bignoniaceae (order Scrophulariales), native to tropical and subtropical regions of the Americas and cultivated widely around the world.
Members of the genus range from shrubs to large trees, reaching 20–30 metres in height. Most species bear bipinnate leaves, though some carry pinnate or simple leaves. The wood tissue is characterised by narrow vessels and splayed parenchyma, with anatomical differences between the genus's two recognised sections.
The flowers are among the most visually striking of any tree genus: they are produced in large, conspicuous panicles, each with a five-lobed corolla in shades of blue to purple-blue (a few species produce white flowers). Jacaranda flowers are distinguished from other members of the Bignoniaceae by staminodes that are longer than the stamens; these staminodes bear glandular trichomes that secrete metabolites attracting orchid bees, making them important pollinators. The pollen is tricolpate and the chromosome number is 18. The fruit is an oblong to oval flattened capsule containing numerous slender seeds, a trait shared across the tribe Jacarandeae.
The genus is divided into two sections. Sect. Monolobos contains 18 species found primarily in western South America, Central America, Mexico, and the Caribbean. Sect. Dilobos DC., regarded as the more primitive form, contains 31 species concentrated in southeastern Brazil, including the Paraná River valley.
The most widely grown species is Jacaranda mimosifolia (blue jacaranda), which has achieved a near-cosmopolitan distribution through cultivation and has naturalised in parts of Africa, Australia, southern Europe, China, and the Caribbean. J. copaia is valued commercially for its exceptionally long bole timber.
Etymology
The name Jacaranda is of Tupi–Guarani origin, entering English via Portuguese. It was recorded in a 1753 supplement to Chambers's Cyclopædia as "a name given by some authors to the tree the wood of which is the log-wood, used in dyeing and medicine." The generic name is also used directly as the common name for the most familiar species.
Distribution
Jacaranda is native to tropical and subtropical regions of the Americas. Sect. Monolobos is centred in western South America, Central America, Mexico, and the Caribbean, while sect. Dilobos is primarily distributed across southeastern Brazil and the Paraná River valley. Through widespread cultivation, J. mimosifolia has naturalised far beyond its native range, becoming established in Central America, the Caribbean, Spain, Portugal, southern and northern Africa, China, Australia, Rwanda, and Cyprus.
Taxonomy Notes
The genus is divided into two sections based on anther morphology: sect. Monolobos (one theca per anther, 18 species) and sect. Dilobos DC. (two thecae, 31 species), the latter considered the more primitive. J. copaia is anomalous and may represent an intermediate form between the two sections. GBIF's backbone records a single accepted descendant for the key used here, contrasting with the widely cited figure of 49 species; the discrepancy reflects differences in synonymy treatment across checklists.
Cultivation
Jacaranda can be propagated by grafting, cuttings, or seed, though seed-grown plants take a long time to reach flowering size. The genus grows best in well-drained, sandy soil in full sun and tolerates both drought and brief periods of frost down to approximately −7 °C (19 °F). Mature plants are more cold-tolerant than young ones; younger plants may not survive temperatures below freezing.
Cultural Uses
Several Jacaranda species are extensively grown as ornamental street and garden trees throughout subtropical regions worldwide, prized for their intense blue-purple floral displays. J. mimosifolia has become deeply embedded in local culture in cities such as Pretoria (South Africa) and Grafton (Australia). J. copaia provides commercially important timber valued for its long, straight bole.
