My late father had plastic containers and oatmeal boxes and sacks of all sorts of flower seeds that I brought back home with me. Since I don't know what most of them are, I've planted them or scattered seeds in the meadow to maybe come up and give me some color this spring/summer. BUT, I found these in an old oats box and I know he used to call them sand dollars like the sea urchins, but I know that can't be the real name of them because I cannot find any photos of the plant looking it up by that name. Any ideas? I was trying to recall how large it grew so I could guess where to plant them around here.