Chlorogos, The Greenspeech

The very wise have always known that the trees can speak to those who are willing to hear them. Oracles can read prophecies in their leaves and druids may divine the health of the land from the shapes of their roots.   Aesk the Ever-changing, in their eternal quest to truly understand every living thing and after spending years conversing with treants, devised a way to read the most hidden messages within any tree—and even to inscribe their own words into this living script.   Nicknamed "Greenspeech", Chlorogos is a written language only, and while a handful of students can glean fragments of its meaning, none but Aesk can claim true mastery. They are able to read the boughs of a tree to determine everything it has "witnessed" since its leaves last fell - the temperature and humidity of any specific day, the animals that have passed within its branches and roots, or the whispers overheard from people speaking nearby.   Using their mastery of druidic magics, Aesk is the only one who can "write" in this language as well - shaping trees and altering the veins of leaves to encode whatever meanings they desire in a living object. They have even gone so far to create a new species of tree whose seedlings whisper with a faint telepathy, allowing Aesk to impress their thoughts upon them. When planted, the saplings erupt into growth, their leaves unfurling with the hidden words etched in verdant veins.