Thanks for all the relies.
Just for the record, I am in Australia so this tree is a native.
Very interesting. So you could expect to see five trunks going down to the ground in a group? Would really like to see a photo of it.
What I am trying to visualise in this case and get my head around, is that if there are say five trunks (or less), I would expect each trunk sprout to grow in diameter eventually. But if each of these new trunks are sprouting from the outer ring of the original trunk (a ring of thickness no more than say 1/2" of cortex/epidermis/phloem etc), won't the diameter of these new trunk sprouts be limited by the thickness of this ring and thus instead limit the diameter of these "trunks" to be more like thin branches?
I would also expect the centre core of the original trunk to perhaps rot quite badly, as the sprouts from the outer ring woudl almost make a kind of "cup" where water and debris would accumulate and rot.
As azrael pointed out, resprouting from lignotubers, is a "last ditch effort" of the tree to flower and seed. It is this kind of "desperation" to survive, somehow that facinates me. Unless we consider bushfires as regularly causing damage/trauma equivalent to the trauma caused by an "un-natural" event such as a chainsaw cleam cutting a the trunk at the base, I am kind of thinking that the tree is reacting to damage/trauma for which it is NOT directly adapted to recover from. In this sense, the fact that it might survive seems surprising.