Visit any Oxfordshire garden centre and you are likely to see images of the Green Man, a leafy face, sometimes disgorging foliage. Pottery garden plaques are especially plentiful, as illustrated in the photograph (left) of an example seen at Waterperry Garden Centre.

The modern motif derives from figures seen in some of the earliest parish churches, and from more ancient traditions yet - certainly connecting with carved heads seen in Roman temples devoted to Bacchus, and perhaps with Eastern traditions too.

In the course of this year's Green Man Trail in Oxfordshire Limited Edition, we have been exploring many historic images seen around the county. It has been very much a collaborative effort in which Oxfordshire Limited Edition readers have contributed their own discoveries - and creations too.

Celia Mosely kindly sent me both a hand-embroidered cushion and hand-painted mug inspired by the Green Man Trail. I treasure both - many thanks!

The Green Man motif crops up all over the place; not only in church carvings and garden ornaments, but in items of furniture, for example.

Nick Wicker, who works at the Sheldonian Theatre in Oxford, has shown me some Green Man chairs in the building. These are curators' chairs - gilded seats of high office in the University.

Valerie Broehl has photographed a more domestic chair seen on sale at an antiques shop on Walton Street in Oxford - very much something for use in everyday life. Many such items of furniture were produced in late Victorian or Edwardian times, neo-Jacobean in style and perhaps speaking in some way to a progressive, Machine Age populace of the older traditions of English history and of the revitalising powers of green nature.

Oxfordshire Limited Edition reader, Pauline Moorbath, showed us a particularly interesting sideboard from this period, at her home in Kidlington. It bears a quite grotesque head, sticking out a tongue.

The sideboard has been in the family for some time, but Pauline told me that two or three years ago, she was given insight into its possible meaning after attending a lecture on the Green Man at the Abingdon Society of Decorative and Fine Arts.

When she described the sideboard to the lecturer, David Bostwick, he suggested that it might, in the context, represent a Victorian morality - a warning against wagging tongues and gossip around the dinner table.

I like this idea, for if I have learnt anything about the Green Man, it is that the figure has meant different things to different people through the ages.

My wife Jo found a Mermaid edition of plays by William Wycherley in our own library. It was published in the late 19th century, and is crowded with little vignettes of foliate heads, some of them horned like satyrs, or Pan himself, the Greek god of shepherds and flocks, of rustic music and of wild places. As a deity of nature he greatly preoccupied artists in the Edwardian period, featuring prominently in The Wind in the Willows, Kenneth Grahame's classic of children's literature, written in 1908.

Today, with environmental awareness so strong a theme in all our lives, the Green Man is seen as an important symbolic figure who unites humanity with nature. One of the most influential books on the subject was William Anderson's Green Man, with photography by Clive Hicks (Harper Collins, 1990). Anderson spoke of the Green Man as The Archetype of our Oneness with the Earth,' and quite early on in our investigation his sister Susan Strachan, from Charlbury, wrote to me to inform me that He first became interested in the Green Man while at Exeter College - so there is an Oxford link!' "We look out for Green Men wherever we go,' Susan added. "In our garden we have a Green Man sculpture and quite a few miniature facsimiles around the house - bought at various cathedral shops! Although we do not have our own Green Man in Charlbury, many of my friends have some kind of image in their house or garden. He seems to strike a chord with so many people."

William Anderson's book, with a connected BBC Omnibus documentary, contained spiritual speculations that more sceptical readers may find hard to accept. But there is no doubt about the book's influence. Oxfordshire writer John Matthews, in his beautifully illustrated The Quest for the Green Man, (Godsfield Press, 2001) continues the tradition.

He interprets the figure as a mythological archetype representing the spiritual intelligence of nature and writes: "He reminds us that we are not the lords of creation, but partners in the vast, living ecosystem that is our planet."

The Green Man today harmonises ecological concerns with New Age spirituality, without apparently offending traditional Christian sensibilities any more than he did in the Middle Ages or the Reformation. In 17th-century East Anglia a zealous Puritan named William Dowsing, as Arthur Mee put it, "smashed his way through 150 old churches in Suffolk", destroying innumerable images he thought superstitious; yet he seems never to have touched any Green Men.

The acceptance of the image in Oxfordshire church tradition too, has been one of the most revealing discoveries on the trail. Christ Church Cathedral in Oxford, for example, is afforested with foliate head carvings that gaze out from the walls, peer down from roof bosses in the cloisters, and grace wood-carved poppy heads in the choir stalls of the Latin Chapel. There, in the gift shop, you can not only buy Green Man books and posters, but even Green Man fridge magnets.

The Green Man is, it appears, alive and well. I am grateful to all the readers who have contributed their discoveries to our features.

One of the most delightful perspectives came from Matilda Webb who sent us the following e-mail.

"Hello. I've been enjoying looking for the places with a Green Man that are shown in your website. Recently my friend Guy Viney came to visit me in Oxford and I photographed his incredible Green Man tattoo . . . I know it's not quite what you're after but it is a Green Man and I did photograph him in Oxfordshire (in Great Coxwell Tithe Barn)."

He does get about, that Man.

The Green Man Trail is an ongoing initiative for Oxfordshire 2007, and if you have any information about Green Man images in the county do get in touch. Visit www.greenmantrail.co.uk for information and updates. To contact us e-mail info@greenmantrail.co.uk