So a year or two ago I ordered about a dozen plugs to Eupatorium fistulosum, Hollow Stem Joe Pye Weed, which gets 5 to 7 feet tall. What arrived on accident was labeled Eupatorium coelestinum, Blue Mist Flower, which gets 2 to 3 feet tall at most. I was okay with the mix up, and they handled it nicely. They said can go ahead and keep the plants they sent and that they were sending me the correct species. As mentioned this was a few years ago, things have established, and grown, and finally the Blue Mist Flower has decided to flower....
I have contacted the nursery about this mix up. I'm not naming who they are because I really like them, though if you bought Blue Mist Flower or Ironweed from them and are having the opposite come up, you probably know which nursery it is. They have a huge selection of plants, so stuff like this does happen.
The exact species probably won't be known for another year or so. Though I have asked if they could ID it for me with less than satisfactory results. Ironweeds are notorious for hybridization. Also plants can be somewhat stunted the first few years they grow. I remember the first year I planted Cup Plant; they were 3 feet tall when they flowered! Today those same Cup Plants range from 5 to 7 feet tall before flowering. A similar thing might be happening here with the Ironweeds. I note they don't have many flowers on them this year either. Perhaps next year it will be more apparent which species they are.
My only gripe here is that I planted them in places meant for 2 to 3 foot tall plants. They're currently at 5 feet, but if they're a certain species they may get to be 8! Not exactly the a charming ground cover I was going for. Again I'm not mad at all. Next year I might have to take a shovel to a few plants is no reason to be angry. Vernonia sp. all tend to be very popular with pollinators. I've already had one hummingbird moth go nuts with one of the plants. I think of the genus as the thornless version of Thistle.