Board Thread:Lore Discussion/@comment-7153552-20130708162914/@comment-9887604-20130908222906

Green Sap could perhaps be in Argonia, it is just assumed to be in Valenwood. Taking it a step further perhaps the Hist could be tied to the tower, perhaps green sap refers to the Hist sap. If you have read Lord of Souls you would learn that there is more to the Hist and Oblivion than stated in game.

The Khajitt themselves could be a tower, if you read their creation myth it talks of their special connection to making sure the moons stay where they belong. They would be required to return them to their place if anything ever happened.