This is a bit esoteric, but the Massive Voodoo has an interesting article on seeking out roots to use as bases for display miniatures. They’d also make some really cool and alien looking tabletop scenery.
I’m reminded of something that John Hill, creator of Johnny Reb, said to me years ago: Nature recreates itself in miniature. Thus, chunks of bark look like rock formations, tree branches retrain the structure of trees, etc.