Pictures please. Closeup of flower, if possible, and leaves/habit. Don't bring them inside to take pictures.

Lotus tenuis, Narrowleaf trefoil, or something very like it.

Interesting seeing it at this time of the year. Those only grow in Phoenix, Arizona during our winters, and then die out in the spring. Their tiny seeds sit there dormant all summer through the blistering heat and scorching sun and drenching monsoon rains. But in late October, when it cools down again, they sprout and pop back up as a weed. Since they're part of the mustard family, I wonder if they are edible?

I find it fairly difficult to tell the difference at this stage, though the seed pods look quite different. The page linked below might help. I have Chelidonium (which has the long seed pods) and am on constant watch for it in spring in the hopes of ripping it out before it goes to seed. There is quite a bit less now than there was when we moved in. Stylophorum is native and gently seeds around here. Chelidonium is a Eurasian import that is quite weedy. Greater Celandine (Chelidonium majus) vs Celandine Poppy (Stylophorum diphyllum)