It looks like Oxalis...I have this,and I find it's easy to control .I have quite a few clumps at the front of a border..a lot don't like this ,but I think it's very pretty..

Yes! I have this too! And the purple version of it!

Oxalis iron cross has purple centre ro leaves as well as pretty flowers

I, too, have this plant and have brought some with me on every house move. It's tough and colourful though the blooms do close if there's no sun. I really love it.

I have done the same,Arbuthnot..each house move,it has come with me..I first saw it growing in a little unadopted lane ,where it must have seeded itself,so as it didn't seem to belong to anyone,so I pulled a small piece up..this was way back in 1983,as I was taking my daughter to pre school Nursery :o) ..and Pam,I had the Iron cross one,but it succumbed to rust each time it got going each year,so it had to go..a shame,as it's so pretty..:o(

Oh haven't seen that Bloomer, it just disappears for so long I wonder if its ever going to grow!

A friend gave me some (she called it shamrock) during the 1970s and it thrived, as it has done in each and every garden I've put it in. Never had any rust at all.

I'm afraid I am inundated with three types of Oxalis and it is taking forever to get it out - it's very invasive.

I've planted it twice here and it didn't survive at all...

The oxalis weed is invasive here so I put iron cross in a big pot.....seems happy enough