No, I haven't. Or at least, not that I remember. Before it was partially eaten, it was nearly six feet high. Do cosmos grow that high?

What about Eupatorium capillifolium?

Some cosmos can get very tall - and it does look like cosmos. Might an animal have dropped some seed? I thought birds liked to eat them.

Thanks, everyone! I think that many years ago I threw out a bunch of seeds from one of those "meadow mix" packets that a neighbor gave me. I'm sure cosmos would have been in the mix. Maybe that's where the forget-me-nots came from. I'm pretty sure I never planted those, either. The whole hillside is very hard to work on (I'm nearly 80) so I mostly just try to pull out the really invasive stuff like porcelain berry, and ignore the rest. We have many, many deer and they are welcome to whatever they enjoy.

Be sure to ID by posting a pic of the flowers

One thing for sure.,..don't let it go to seed without an id

Ken

Haha, thanks Ken! That's for sure!

I'm glad that I didn't pull the plant because it finally bloomed. The flowers are very small, about the size of a quarter, but maybe that's because it's not getting enough sun. They don't look like any cosmos flowers I've ever seen, though. They don't have the delicate appearance of cosmos.

Google Coreopsis tinctoria, Plains coreopsis.

Thank you callirhoe! I'm sure it came from the "instant meadow" seed packet that my neighbor gave me ten years ago! I remember tossing the contents out onto the steep slope of my side yard. A wallflower popped up there a couple of years ago. Who knows what will be next!