"That buzzing-noise means something. If there's a buzzing noise, somebody's making a buzzing-noise, and the only reason for making a buzzing-noise that I know of is because you're an insect. .... And the only reason for being an insect that I know of is slurping nectar ... " With apologies to A. A. Milne
This is an angophora hispida which is a genus of about 10 species that are commonly called "Apples", because some species have a growth habit similar to that of the apple tree. Along with Eucalyptus and Corymbia, the plants are generally referred to as "eucalypts" and in common parlance as gum trees - 'cause that is what they ooze. These images were of specimens along South Dowling Street - a major arterial road from the CBD to the airport - close to the East Redfern footbridge. It took me an hour to travel about 20m - the Heart Foundation would not give that a tick!