is it a cultivated plant or one of you wild flowers/natives. where abouts in the usa are you? But I must say its very pretty.

sorry I don't know what it is, but welcome to GoY.

Thank you. I live in Kansas, just southeast of Topeka.
The flower was here, when I moved here in 1990, so I don't know it's history. The yard was really neglected, so I was not to impressed with this plant.

It has been in its current location for about 3 - 4 years. I moved it to a north location, near a wooded area so it seems to be doing better in its new location (away from wind perhaps).

As it is maturing, it is spreading and the leaves are getting larger.
The leaves have a smooth feel to them. I think, it self sows. The flowers resemble a tiny lily. As it grows and develops a root system, it has shoots of new growth. It dies back in the winter, blooms until frost. Easy maintenance, I've pretty much just ignored it just to see what it does.

I looked under KS wild flowers but could not locate it and several books, and Web sites. Thank you for responding to my request.

The leaves look like potato leaves so could it be a solanum of some kind?

I'll research, thank you.

Wild four o'clock, persistence in my internet search paid off!