On last week's extensive tall perennial plant list I forgot to add the big daddy of them all: Vernonia altissima 'Jonesboro Giant,' a lovely 10-12 foot ironweed. (And here's my tall plant list.)
I bought mine from Plant Delights last fall, after being on a wait list. It was found in Arkansas, and as per the description: "The giant clumps sway a bit in the breeze, but so does the Sears Tower. Warning lights may be required in some jurisdictions...please check local flight path maps."
Below is mine, aleady at 10' (the fence is 6' for comparison). Unfortunately, an early wind storm pushed it toward the clump river birch, so they are fighting for sunlight, but the stalk is quite sturdy and thick now in late summer.
If you want this herbaceous perennial beauty, go here. Why wouldn't you?