There are several of these plants growing in my garden in northern Virginia, all in places in which I might conceivably have sowed seeds for it.

It resembles the Lobelias growing next to it, but I suspect that it's a weed.

Please help i.d. it!

Compare with American burn weed (Erechtites hieracifolia).
https://oak.ppws.vt.edu/~fless...
Good addition to the compost pile...
I'm never too concerned about this plant, it gets large... but remains one of the easiest weeds to pull...
The reason there is always so many of them is that the seeds resemble dandy-lion fluff... and blow over from the patch down the street...

Ah, yes, I thought it looked familiar. I have had Burn Weed in my garden before.
Thank you very much!