Mystery in ontario

Another mystery from one of my online groups (this one, the gardeners on a horse discussion board). A volunteer that came up in a donated pot of mums and salvia on Ontario.

The tall stick with very finely cut leaves coming up at the back of the grey pot.

 

Cosmos bipannatus?

 

Cosmo was one of my first thoughts but the leaf margins are much more irregular and spiny. I'll see if I can get an image that better shows the leaves.

 

Reminds Hibiscus coccineus. Any flowers or flower buds ?

 

Does not appear to have flower buds.

Here are some closer up photos and a picture of the top, apparently it is 7'-4" tall.

 

Remind me Artemisia biennis. If so, will probably be flowering next year.

 

Thank you, that is the closest so far. I guess we have to wait until next year.

 

Crush a bit of the foliage and describe the scent?

 

Here is the scent description from the pot owner

 

Not Artemisia biennis then, which should be scentless. That's not to say it isn't a different species of Artemisia though.