Perhaps Euphorbia amygdaloides Here is a link that might be useful: Euphorbia

Veratrum? -- just a guess, post pictures of older,please.

i'm actually really surprised it wasn't ID'd either, especially when you consider the competency i've experienced with the people i'd asked in the past (although the near-dozen people at Lowes, Home Depot and Ace weren't expected). i think the problem was my inclination to suggest i thought it was some variant of eupatorium. i think if i would have broken a leaf off and smelled it, i would have figured it out on my own - this is what worked for the two anise hyssop that came up on my side yard unexpectedly, and the tomatoes too. why wouldn't one of the MGs do the same, i wonder? either way, i really appreciate the ID. it's beautiful. if it wasn't such a profuse seeder, i'd put it in one of my raised beds with (the profuse seeding anise). maybe i'll do it anyway and try to control by pulling the seed heads. :)

Are the stems a ruddy color? Sounds like Preziosa to me. Lowe's is selling a ton of them right now I've noticed. Another thing I've noticed about hydrangeas is that when stems and leaves are colored like the blooms, it tends to keep the blooms in the same color range in a wider variety of soil types. Check out this vendor's picture for accuracy: http://www.hydrangea.com/shopping/pgm-more_information.php?id=34