This has lovely little flowers like that and it reseeds itself. Underneath the soil, hard bulbs form and this can be invasive. The height is about 4-6 inches tall. Any clues?
I agree with Oxalis, there are over 500 Species in the Genus but many with more leaflets than yours. They can be very invasive in the right area but pretty
Here's a third vote for Oxalis. Like Baa said, there are so many kinds and some can easily be invasive. A neighbor has some lining her shade garden beds ~ little pink blooms about 1/4" across and leaves 3/4" to 1". I have some that are growing wild under the trees in the pastures ~ haven't seen a bloom, but the leaves are easily 1 1/2" or more. I don't know if it's native/indigenous or escaped and naturalized, but they've been here forever.
Be very careful with that one, this is my #1 WEED!!! Gives me the biggest headache of them all, it not only seeds itself, but makes dozens of little bulblets each year which drop off if you try to dig it up. Don't let that one get loose in your garden or you might regret it.
It's Oxalis latifolia, from South America I believe.
I'll check on that, Maddy. Yes, it seeds itself and it sees to it that some part of the bulb remains in the soil if we dig up!!