Here is the final finished piece. I decided to use a dark green wool felt as batting, backing, and border (how's that for economizing on time and materials!) and hung it from a natural branch from the backyard. I've tried to think of something else to call it, but "Photosynthesis" just seems right, obvious or not. I don't usually work abstractly and I almost didn't bother taking part in this challenge, but I do like the final piece. So it pays to push yourself outside your comfort zone sometimes.
Now the holiday rush is on and I still have many more bookmarks waiting to be finished, as well as the Waterlilies piece for my inlaws, which still needs a border and binding... St. Nick won't be the only one burning that midnight oil!