I love the branching structure of so many natural things. Trees, of course; and antlers. Coral. Rivers and blood vessels. Hands. Families.
This motif is fractal. If you zoom out, you see it repeated at a larger scale. A twig is just like a branch, which is just like a tree. If you zoom in, you see it repeated at a smaller scale. The bronchi lead to ever smaller and smaller bronchioles, which lead -- eventually -- to the tiniest of blood vessels.
It's growth as a repetition of the same form at different scales. Theme and variations.
As part of a provocation about growing things, I had a tumbleweed in my Grade One classroom. We had already turned it upside down, and shaken out the seeds; then planted some of them and watched them germinate.
Then I set the tumbleweed on top of an old overhead projector and turned the projector on. On the wall, the plant drew an elegant self-portrait; a line drawing rendered in the medium of shadow. I taped up a full-sized sheet of watercolour paper to capture these beautiful lines. I left out a few Sharpie markers, and left this set-up in place for a few days. Kids took turns tracing the shapes of the shadow branches.
Next, I removed the drawing from the wall and taped it down to a table. I left out blue watercolour paint in several shades. I wet the whole page down with clear water, and the kids painted the blue all over, wet-into-wet.
Finally, when the paper was dry, we painted the large branches with a brown watercolour wash.
At the same time, we were drawing trees. We were looking at slabs of wood, cross-sections of trees that revealed all of the annual growth rings. I showed them Bryan Nash Gill's prints made by inking tree slabs and pressing them onto paper. We learned about "heartwood" at the core of the tree, the central structure from which growth begins.
We learned that growth comes from the heart, and reaches out in every direction.