My weed bloomed...any ideas what it is?

This one was a stumper last year...even a family name would be a start.

It's about 4 feet tall, growing in pure sand on the banks of the Columbia River near Portland, OR. The roots are all interconnected. All this growth is from about 2 inches tall this year. I think the main plant dies every year and grows from the roots again, don't remember.

 

Flowering plant may be a Solidago sp.
The creeping plant in the middle picture is a grass.

 

Yes: the creeper is not the same plant as the one in bloom.

 

Sheesh, I went up and pulled some up and you are right. That's what I get for just assuming.

It does look very close to a Solidago
http://www.missouriplants.com/Yellowalt/Solidago_juncea_page.html