Australia wattle
This stamp was issued by Australia in 1982 featuring, along with another two postage stamps, old Christmas cards
I found this interesting link which helps to identify the plants on Australian Postage stamps
https://www.anbg.gov.au/stamps/stamp.835.htmlAs you see they are not sure just which Acacia this stamp depicts but guess that it might be
Acacia dealbataI searched for an article in THE MEDITERRANEAN GARDEN mentioning this plant and actually growing in Australia but in the end ran out of time
However, there is no shortage of articles mentioning
Acacia dealbata growing in Mediterranean gardens
I chose issue number 60, April 2010 for you to read
THE ENCHANTING SCENTS OF A MEDITERRANEAN GARDEN by Helen Pizzi
I am including a photo from my archives named
Acacia dealbata but I might be mistaken in the identification