Glasswood

This curious tree is the main source of building material in the Deeganverse - probably, because the inhabitants have not figured out that the green triangular mountains surrounding them are trees as well. They are hardly to blame for that. Unfortunately, glasswood has very poor properties as building material, for, true to its name, it is prone to shattering in a glass-like manner. For this reason, higher Castes prefer to live in stone-houses, while listening gleefully to the painful screams of the lower Castes as those are slashed to shreds by their walls and furniture.

A second theory persists, however, which maintains that glasswood is actually not wood at all, and that lower Castes instead choose to build their houses out of baked pottery painted to appear like wood. Which, again, would be well within the limits of their stupidity, lacking a First Caste character to lead them.