For an introductory discussion of these things, see my weblog entry of July 21. This is the last set until the "fall show".
Today, peonies of the Caucasus.
Carpels of Paeonia caucasica.
Carpels of Paeonia mlokosewitschii (the Golden Peony).
Carpels of Paeonia tomentosa.
Distinctive carpels of Paeonia steveniana. Much like those of obovata (of 2 days ago) but fatter and green rather than blue-green.
An observation: P steveniana is also called P wittmaniana subsp macrophylla and less commonly P wittmaniana subsp nudicarpa (appropriate to the obviously nude carpels!); and P tomentosa is also called P wittmaniana subsp tomentosa or just P wittmaniana. It's not obvious from the carpels that the two deserve to be part of the same species, but of course there is more to botanical classification than that (please don't ask me what though).