Not entirely clear what you seek ~~ Green Man as symbol of regeneration as used as an architectural manifestation? Or archetypal association with forestry. Robin Hood in the Greenwood has been much associated with some manifestations of the Green Man myth: so some Robin Hood ballads might be a point to start. If you could make your requirements & criteria a bit clearer, I think more suggestions would follow.

Best of success in your endeavours --

~Michael~