I can't clearly see the leaf but the flower looks much like a tickseed (correopsis)Some varieties are annual and some are perrenials that die down to the ground in winter so it may be a perennial and not an annual. Tickseed comes in many varieties that may have a single daisylike flower or a double flower like in your pictures. Check out the link below for photos of tickseed

Here is a link that might be useful: tickseed

Yes, this is the Coreopsis. I was in Home Depot and it is selling exactly the same plant. This is a lovely flower and I plan to collect the seeds and spead in other places.

More photos:

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This is an aggressive seeder, so I wouldn't waste too much time collecting them. In the garden they can be too bully-ish. In the meadow/prairie their competition helps keep them in check.

Aggressive? It does not seem so at our land. Our open land is about an acre and our neighbor keep a 3 acres land open. And this is the open patch of Coreopsis I've seen. The entire 4 acre land is dominated by goldenrod, milkweed, sulfur cinquefoil and Mugwort.

Even black-eyed Susan sends far more plants than this plant. Coreopsis sends beautiful flowers.

Also, since this is open land, I'd rather want to have more wounderful wildflower.