Thanks for that ID. I googled it and came up with a lot of information. The species tend to be invasive but apparently some of the more recently developed modern varieties aren't so invasive. There were at the top of a trail called "1000 Steps" which goes up a mountain side. It's a popular walk and I've done it a number of times with a niece when I've been visiting them. This time all these were blooming. They looked like they might have been escapes from some nearby housing.
