Callistemon! Edit - Callistemon citrinus has been reclassified as Melaleuca citrina. AKA the common red bottlebrush, crimson bottlebrush or lemon bottlebrush. It's endemic to Eastern Australia. Therefore...
It's quite common in the parks and gardens in the South of France, where it's nicknamed "rince-bouteille" (bottle rincer).
I didn't know it came from Australia.