Malva arborea I think? Edit: Nope, Malva sylvestris

I would agree with Malva sylvestris. IME, it can self-seed prolifically in areas where it is happy growing.

It is more than happy to take over the world, with roots that grow down to Australia. I love the malva family, but sylvestris, not at all. One of my most persistent and dire weeds (from neighbouring plots) which I whip out quicksmart.

Susy Jackson, how do you like your Callirhoe bushii? I keep mine on a short leash. I just got seeds for clustered Poppy Mallow, Callirhoe triangulatum. My Malva zebrina lasted a long time. The seeds must stay viable for a long time? Abelmoschus manihot is similar. I have an Abelmoschus vollunteer now. I like Malva alcea and it's the species I'd grow if I grew Malva again. Unfortunately my climate is too cold for a serious Flowering Maple obsession. I don't need tropicals to be happy and content.

Thanks all. Does Malva sylvestris spread from the roots? I've not noticed it doing so but this is the first time I've had it in my garden.

For what its worth, I've lived in Cascadia for more than 20 years now and dozens of aggressive species of garden plants have tried to invade my (six) gardens.....but not Malva sylvestris, which I had to invite! We will see how this plays out.