I didn't know this one was over the back (there is a small scungy one back between the playing fields). And its HUGE. And all out in flower. With Red Wattlebirds, noisy miners, King Parrots, Crimson Rosellas, Blue Faced Honeyeaters, Satin Bowerbirds all trying to get in but being chased out by the multitudes of Red Wattlebirds. I call it the "oxy" gum because I can never remember its name!
The bark is an ironbark - hard, coarsely fissured, grey-black. Closely related to Yellow Gum. Based on location and buds > 3 it is most likely Red Ironbark aka Mugga Ironbark (Eucalyptus sideroxylon) which has 7 or more, if they have not been broken off by one of the birds it attracts. Lovely image in flower, a very important species for nectar feeding birds and insects, as you are seeing first hand :)