There is no evidence that I'm aware of to legitimise the conflation of the Green Knight and the Green Man - unless you've been reading the "scholarship" of Mike Harding. Where is the evidence for the Green Man being a pagan symbol?

Sedayne: hurrah! Excellent point about the absence of Sheelaghs and Green Men in The Wicker Man. It's a goood demonstration of how the co-option of these "ancient pagan" symbols is really relatively recent. I was given the film for Christmas as a joke, and haven't been able to bring myself to watch it yet - tonight may be the night! :0)