I don't have a picture because so I'll try to describe it.
When I was young there was what I think was a ground cover-type plant (it was low to the ground but sort of poofy).
It looked like pretty densely packed tiny tiny clovers (in that each "sprout" had three little leaves in a clover shape, only miniature, and it was green) and you couldn't see the ground below. It was very delicate, and covered the shadier, damper areas of our lawn in large patches. Because it was so fluffy and delicate, any place you would step on it, it would compress and leave a foot mark in the groundcover.
Since this was so long ago, I'm not sure if this is correct or not, but i believe it would at least occasionally sprout little tiny white flowers.
Thanks for any help in identifying this plant--it brings me nostalgia of childhood.
Thank you for your responses!
The oxalis oregana is really close, but the leaves seem pretty large compared to what I'm trying to describe. It's pretty much just like the oxalis oregana, only a lot more tiny.
There are many different Oxalis, but I would have no idea what kinds grow in CA.