Botanists fought for years over who gets to keep the name Acacia
The word acacia first described an African tree growing in Roman Egypt. Today it belongs mostly to Australian wattles, after a bitter botanical dispute that ended in 2005 and was upheld at a congress in Melbourne in 2011. Around 1,084 species now carry the name, almost all of them Australasian.
Wattles are shrubs and trees of the pea family, bearing fluffy spikes or balls of tiny golden to creamy flowers and seed pods with a fleshy tip on each seed. Some adult plants swap true leaves for flattened stalks called phyllodes. The word acacia goes back to a Greek term for a preparation made from Vachellia nilotica, rooted in a word for point, while wattle comes from an Old English name for woven sticks used in walls and fences, applied to these Australian plants since about 1810.
Until 1986 the genus was thought to hold about 1,352 species. That year Leslie Pedley argued it was not one natural group and proposed splitting it three ways, with most species going to a genus called Racosperma. By the early 2000s DNA made the problem plain: the huge Australasian lineage was not closely related to the smaller African group containing the original type. Normally the Australians would have had to rename. Instead they proposed a new type species, and critics warned the switch would shift the costs of renaming onto developing countries in Africa, Asia and the Americas. The Australian side won, and the African and American lineages became Vachellia, Senegalia, Acaciella and Mariosousa.
In Australia, acacia forest is second only to eucalypt forest, covering 980,000 square kilometres. Aboriginal people ground the seeds into flour for pastes and cakes; wattleseed can hold up to 25 percent more protein than common cereals. In the 19th century Australian bark was shipped to European tanneries, a ton yielding about 68 kilograms of pure tannin.
Exported, some species turned into problems. South Africa brought them in from 1847 to hold coastal dunes and in 1864 planted black wattle for tannin; it is now the country's most widespread invasive alien tree, and at least 16 introduced species count as invasive there.
Source: Acacia
