Way back in the early chapters, I did a few drafts of the Wind Tree/Heart of the Forest before settling on a final design. It's mostly a wild cherry tree, but a bit more spindly, and with dangling seed pods instead of small fruit.
For the other trees, my brain pretty much just told me, "The Earth Tree is an oak with wide roots and simpler leaves. The Water Tree is a willow with some wave patterns in the branches and roots. The fire tree has permanent autumn colors, the canopy is shaped like fire plumes and it has the trunk of a joshua tree. No further notes."
