Arbozoic trees were a species of tree that dominated the ecology of the planet of Aleen. The trees dotted the landscape of the surface of Aleen, while the root systems of the tree constituted over half of the living matter on and in the world. The Underworld was largely carved by the roots of the arbozoic trees, which spread out into the crust of the planet for kilometers. When a tree died, the roots rotted away to nothing from the inside out, leaving behind the caverns that comprised the habitat of the Kindalo. The seeds of the arbozoic trees were crystalline in nature, with a strange glow that could not be traced to a known chemical composition.