Hey, i'm having problems adding texture to leaves, somehow every time i add any leaf texture it adds also a texture of bark (Optimized Bark Material). I can see it in "Mesh Renderer" but i cant change it.
The mesh renderer component is going to display all the materials for that tree. To change the texture of the leaves you'll need to select the leaf node and change it under "Geometry".
You'll see a section for material. Most of the time Unity will give you a small warning when trying to add leaf materials with something like "this shader needs to be converted to a tree shader" before it applies the leaf material. It'll be directly under the geometry section.