Vachellia farnesiana, also known as Acacia farnesiana, and previously Mimosa farnesiana, commonly known as needle bush, is so named because of the numerous thorns distributed along its branches. The native range of V. farnesiana is uncertain. While the point of origin is Mexico and Central America, the species has a pantropical distribution incorporating northern Australia and southern Asia. It remains unclear whether the extra-American distribution is primarily natural or anthropogenic. It is deciduous over part of its range, but evergreen in most locales. The species grows to a height of up to 8 m (26 ft) and has a lifespan of about 25–50 years.
The plant has been recently spread to many new locations as a result of human activity and it is considered a serious weed in Fiji, where locals call it Ellington’s curse. It thrives in dry, saline, or sodic soils. It is also a serious pest plant in parts of Australia, including north-west New South Wales, where it now infests thousands of acres of grazing country.
The taxon name farnesianais specially named after Odoardo Farnese (1573–1626) of the notable Italian Farnese family which, after 1550, under the patronage of cardinal Alessandro Farnese, maintained some of the first private European botanical gardens in Rome, in the 16th and 17th centuries. Under stewardship of these Farnese Gardens this acacia was imported to Italy. The plant itself was brought to the Farnese Gardens from the Caribbean and Central America, where it originates.Analysis of essences of the floral extract from this plant, long used in perfumery, resulted in the name for the sesquiterpene biosynthetic chemical farnesol, found as a basic sterol precursor in plants, and cholesterol precursor in animals.