Or Green Man. Primarily the name given to a leafy head found carved in medieval churches throughout Europe, particularly in Britain. Believed to be a remnant of a pagan cult.
Related to a character in Mumming Plays and various medieval festivals, called Jack-In-The-Green, where he represents the spirit of spring and vegetation. The two names eventually becoming synonomous.
Also found in folklore as Jack-In-The-Green, Robin-In-The-Green or Robin-In-The-Wood (related to Robin Hood) and many other variants
The image is thought to derive from Roman times. The foliate head is found wherever Roman Legions were based.
One head in France bears the carving 'Silvanus' (the Roman god of the Wild Wood and pastoral animals), but myth experts and archeologists question the authenticity of this attribution (this popular god was never depicted this way elsewhere), and point to the late date of the head. Other candidates include Dionysos (one is carved on a temple to Bacchus in Iraq) and Osiris (painted green in Egyptian tombs). But the deity was probably Romano-British, absorbing many Celtic archetypes.