-Northeastern Indiana in a mostly bare field. Full, all-day sun.

I'm not having any luck locating an ID for this plant that just suddenly appeared en masse; maybe you can help? The bud makes me think that I should be familiar with it already, so if I've asked previously, I apologize.

Moth Mullein (Verbascum blattaria), I think.

http://www.missouriplants.com/...

Thanks, Kent.

I'd wondered about that one but the site I was looking at didn't offer leaf images. It looks like a match to me.

One site says, "An extract of moth mullein has been effectively used to control mosquito larvae." http://www.oardc.ohio-state.ed... , so maybe I should add it to my rain barrels.

...and "Seeds of moth mullein have been found to remain viable for 90 years." (!!) So maybe I'd do well to remove any buds first.