False acacia Robinia pseudoacacia

The black locust or false acacia is perhaps one of the most confusingly named trees in the world as it has little to do with either locusts or acacias, and is in fact one of our most environmentally-friendly species.

Some common names for trees are so deeply embedded in history that, even if they are misleading in the extreme, they tend to remain. The black locust (Robinia pseudoacacia) or false acacia is one such example.

The 'locust' part of the name is said to have been provided by Jesuit missionaries who imagined that this was the tree that provided part of John the Baptist's diet in the wilderness. However, this tree is a native of North America so that theory holds no water. (Ironically, the tree itself is well-known for being drought resistant and actually grows more strongly when water is scarce).

The confusion doesn't end there, because if John did eat from a tree and not actual locusts, it was most likely from the carob tree (Ceratonia siliqua). Indeed, neither tree has anything to do with locusts beyond the fact that the Greek word is the same for the insect and the carob pod, which bore a physical resemblance to each other.

Finally, the false acacia name comes simply from a literal translation of the Latin name, where 'pseudo' means false.

Introduced to Britain around 1636, Robinia pseudoacacia is now less common than it was in the first half of the 19th century when the author of a book called The English Gardener, William Cobbett, promoted the use of its wood as an integral part of shipbuilding. He made a living out of buying and selling the trees before iron became the material of choice in that industry.