List of functional material classes - keywords

Hi, I am using Enscape with Sketchup, and would like to know if there is a list of all the material classes that are functional in Enscape, like glass, aluminium, and foliage for example?

Also, can anybody recommend good ("realistic") trees that do not slow Sketchup/Enscape too much?

Thank you!

thank you! Exactly what í Washington looking fór.