I'm really curious about how the celestial mechanics work in this world. Does the sun not apparently move through the sky over the course of the day? There should be only the tiniest sliver of land at the very base of the tree that is in shade all day long, and even this wouldn't be any different from what lots of places on Earth experience in the shadow of various geological formations (Canyons, north/south facing mountainsides, etc.) There are lots of plants that thrive in full shade all day, every day.