Board Thread:Lore Discussion/@comment-7153552-20130708162914/@comment-9887604-20130909003743

It is assumed it is Falinesti. I am taking this straight from the source material.

"Aldmeris bore witness and built the remaining towers during the Merethic: White-Gold, Crystal-like-Law, Orichalc, Green-Sap, Walk-Brass, Snow Throat, and on and on, "aad semblio impera.""

- Nu Mantia Intercept, letter 5

That is the only reference to Green sap, everything else is extrapolation.