I have this plant to and no idea what it is.Mine grows 6ft tall or so and around 2/12 to 3ft wide and is covered with yellow flowers.Perennial here,doesn't reseed that I've seen and no idea where it came from.I've had mine for about 6 years.Bothers me to not know what it is.

I have not figured out just what that is yet either but it grows prolifically and gets a very large root that can go quite deep in the soil if allowed. I think it is an annual and grows from seed.

I wish that you would post this in the Name This Plant forum. I believe it to be dodder, a parasitic plant, but would like the experts in that forum to look at it.

That oenethera will spill out a million tiny seeds the size of pin heads. I thought I'd warn you!