we thought first it was jerusalem artichoke but also could it be a tall cosmos?

Looks like a daisy (black eyed susan) that has maybe been trained as a tree?

Hey there, its not a Rudbekia(black eyed susan)- ray florets are wrong, and the leaves are wrong for Cosmos. Im thinking Helianthus (wild sunflower), or maybe a Coreopsis??

Jerusalem Artichoke (Helianthus Tuberosus} is my guess.

I think if I have to choose from above, it would have to be Helianthus decapetalus (thin leaved sunflower). Same family as the Jerusalem artichoke but I find that the leaves don't match as well as the sunflower. To be careful though not all the flowers or leaves in the Helianthus family are close but, like I was saying, I think the decapetalus is the closest. I am going to say that even though it's not a daisy, some of the other choices look a lot like daisies as well. :)

yes, the daisy family (Asteraceae) can be very confusing...I think we'd need some pretty detailed measurements of characters to distinguish if this is H. decapetalus, or H. tuberosus. I bet Scooby -do and the gang never had this much fun solving mysteries.

I think we'll let this one pass as unknown or at least unsure. Please upload another closeup photo if you can and we'll have another crack at it.