And that is where I nabbed this idea:
Flowers AS paintbrushes.
We paint regularly around here, using a variety of paints: watercolor, acrylic, finger paint. We have learned the character and limitations of each. It was fun to watch the kids explore a familiar media with an unfamiliar tool. We used black-eyed susans and queen anne's lace as that was what was in the vase at the table. This will be interesting to try again next year, with a wider variety of flowers.