Aconitum noveboracense - Northern Blue Monkshood
Might not be as exotic, but It’s definitely on my bucket list. I went out several times looking for this plant in Iowa where I had read there were confirmed observations previously. I never had any luck.
I also read about some on private property in Iowa, so I might have to get in contact with the land owners to go see if I can take a look. There are populations found in other states that might be easier to find and worth checking out as well.