Mike and Steve - if this plant is still around would be good to collect as a specimen and deposit at CSIRO, as I am pretty sure this is the first record of it being naturalised in the ACT. It is on Paul Downey's ACT weed alert list as a medium risk species. FYI @ACT Bio-security
It is in an accessible spot beside a track so I was going to leave it until it flowered. If it shows no sign of buds in the next couple of months I will collect it.