Perennial poppy. I think it was sold as a "California Poppy" but I don't know the species/cultivar name. Anyone know?

Oh, and that is a 5-1/4" board behind it in the first photo, just for sizing. The reproductive parts there are nearly the size of a golfball.

Our California poppy is much simpler with a single petal color -- usually a bright orange but variations include near white, pale yellow and a warm red orange -- not nearly so much texture to the petals and open lacy foliage.

I think your poppy is beautiful and I'm trying to grow more traditional varieties in my garden. I've got a Shirley poppy that looks similar but has pink petals.

You can let the seed pods dry and, when they're fully dried and you can hear the seeds rattle around inside, you can sow them in your garden in the fall and hope to have a good display in subsequent years.

The wikipedia has a page with numerous pix that may be helpful. For some reason I'm not able to post the link to it. Just google "California poppy".