Vachellia nilotica

Vachellia nilotica, more commonly known as Acacia nilotica, and by the vernacular names of gum arabic tree, babul, thorn mimosa, Egyptian acacia or thorny acacia, is a flowering tree in the family Fabaceae. It is native to Africa, the Middle East and the Indian subcontinent.

Taxonomy

This species of tree is the type species of the Linnaean genus Acacia, which derives its name from Greek ἀκακία, akakía, the name given by early Greek botanist-physician Pedanius Dioscorides (c. AD 40–90) to this tree as a medicinal, in his book Materia Medica. The genus Acacia was long known not to be taxonomically monophyletic, and despite being the type species of that genus, A. nilotica has since been moved to the genus Vachellia, with the genus name Acacia being reserved for Australian species; the principle of priority, which would normally prevent such a taxonomic change, was waived with a majority vote by the International Botanical Congress in 2005. The renaming of the traditional Acacia to Vachellia remains controversial, especially in Africa, where V. nilotica is an iconic species and is widely referred to as "the acacia". For the new classification of this and other species historically classified under genus Acacia, see Acacia.

The genus name Acacia derives from ἀκακία, which may come from the ancient Greek word ἄκις, ákis, "thorn", for its characteristic thorns, or may have been borrowed from a pre-Greek language. The specific epithet nilotica was probably given by Linnaeus from the tree's originally known range along the Nile river. In Australia the tree is known as a prickly acacia, despite usurping Dioscorides' two millennia-old etymology, the Australian species classified as Acacia in Australia do not have thorns.

Description

Acacia nilotica or Vachellia nilotica is a tree 5–20 m (16–66 ft) high with a dense spheric crown, stems and branches usually dark to black coloured, fissured bark, grey-pinkish slash, exuding a reddish low quality gum.