Jacaranda mimosifolia is a sub-tropical tree native to south-central South America that has been widely planted elsewhere because of its attractive and long-lasting violet-colored flowers. It is also known as the jacaranda, blue jacaranda, Nupur or black poui. Older sources call it J. acutifolia, but modern authorities usually classify it as J. mimosifolia. In scientific usage, the name "jacaranda" refers to the genus Jacaranda, which has many other members, but in horticultural and everyday usage, it nearly always means the blue jacaranda.

In its native range in the wild, J. mimosifolia is listed as Vulnerable by the IUCN.

The tree grows to a height of up to 20 m (66 ft). Its bark is thin and gray-brown, smooth when the tree is young but eventually becoming finely scaly. The twigs are slender and slightly zigzag; they are a light reddish-brown. The flowers are up to 5 cm (2 in) long, and are grouped in 30 cm (12 in) panicles. They appear in spring and early summer, and last for up to two months. They are followed by woody seed pods, about 5 cm (2 in) in diameter, which contain numerous flat, winged seeds. The blue jacaranda is cultivated for the sake of its large compound leaves, even in areas where it rarely blooms. The leaves are up to 45 cm (18 in) long and bi-pinnately compound, with leaflets little more than 1 cm (0.4 in) long. There is a white form available from nurseries.

The unusually shaped, tough pods, which are 5 to 8 cm (2 to 3 in) across, are often gathered, cleaned, and used to decorate Christmas trees and dried arrangements.

The wood is pale grey to whitish, straight-grained, relatively soft, and knot-free. It dries without difficulty and is often used in its green or wet state for turnery and bowl carving.

Jacaranda mimosifolia is native to southern Brazil, Uruguay, Paraguay, northern Argentina (Salta, Jujuy, Catamarca, and Misiones provinces), and southern Bolivia. It is found in the Dry Chaco and flooded savannas, and in the Southern Andean Yungas of the eastern Andean piedmont and inter-Andean valleys, up to 2600 meters elevation. In its native range, the tree is threatened by uncontrolled logging and clearing of land for agriculture, and is assessed as Vulnerable in the IUCN Red List.

The jacaranda is regarded as an invasive species in parts of South Africa, Namibia, and Queensland, Australia, where it can out-compete native species.

The taxonomic status of the blue jacaranda is unsettled. ITIS regards the older name, J. acutifolia, as a synonym for J. mimosifolia. However, some modern taxonomists maintain the distinction between these two species, regarding them as geographically distinct: J. acutifolia is endemic to Peru, while J. mimosifolia is native to Bolivia and Argentina. If this distinction is made, cultivated forms should be treated as J. mimosifolia, since they are believed to derive from Argentine stock. Other synonyms for the blue jacaranda are J. chelonia and J. ovalifolia. The blue jacaranda belongs to the section Monolobos of the genus Jacaranda.