I thought that when I collected seeds from Paeonia plants during a hike in SLO California, I originally thought they were Paeonia brownii. Recently I have come to believe that I made a mistake and the plants were actually Paeonia californica.
This is an image of the seeds I collected.
I went to the Jepson Herbarium to check it out.
Currently there are a couple of Paeonia seedlings growing in my succulent garden.
California Native Plant Society