The Blue Gum tree is part of the Eucalyptus family. This Australian tree was originally introduced to South Africa by a British botanist, Sir Joseph Banks. The Blue Gum grows extremely rapidly and is able to consume 2,000 litres of water per day! Interestingly, I believe that the tree was originally introduced into the Johannesburg area for the production of timber for our mining industry.
I've noticed over the past few years that many large Blue Gum trees have been removed from the area in which I live. The negative impact that this tree has had on our environment has caused it to be regarded as an invader that should be removed.