I won't even attempt to ID your beautiful Peony...too many colors, types, etc. to wade through. Check out the website linked below and I bet you can find your plant. Its an excellent Peony resource. Rosie Here is a link that might be useful: Peony List

It is a wonderful plant. I love it! The flowers start out with a tinge of pink and turn white as they age. The musky fragrance is quite nice too. I just wish I knew its name...I vaguely remember the common name being Tibetan Tree Peony, but I bought it probably ten years ago and I can't find any Tibetan Tree Peony images that look at all like it. Oh well, I guess it will stay a mystery for now.

Peonies are wonderful -- you're lucky you have some volunteer ones (I'm wondering where they came from, since it doesn't sound as if you have any others? Did someone give you the iris this year?) I've had peonies for years and other than the fact that if you transplant them, they need several years to get their act together and start blooming, they are wonderful! Fragrant, old-fashioned (some are single, some are double blossoms), and what I really like is that after the blooms (when they do bloom!), the foliage is really quite lovely right up until frost. It'll look just as it does now. They shouldn't get more than about 2-2.5 feet tall and if you leave them alone, they'll form a lovely, wide clump. I use peony hoops to keep the flower heads from breaking under a heavy rain or whatever. I didn't see any evidence of buds in your picture (the buds on mind are about to open, so you'd have them by now if you were going to, I think), so I'm guessing you won't get flowers this year, but for sure keep the plant! There is nothing as lovely as a peony -- my mom used to float them in water in a cut glass vase. The only thing they get is ants, which love the sugary sap from the buds. They do no harm, but you'll see them if you have buds. Hope this helps -- congratulations on having a lovely freebie! (Oh, and in the spring, you can tell where they are because they come up with deep reddish pointed shoots, angled different directions. Quite distinctive -- you can't miss them.

I don't know much about peonies yet but agree, it sure looks like my Shimadai Daijin.