Strikingly, a track is marked on the tithe map crossing the intersection of Pepsels, Nether Rackets, Pipsels Mead and Ten Acres fields. This track might have passed straight through the stile in the yew tree. The track – a tunnel of dashed lines on the map – goes no further, as if it led to something no longer there. The countryside is marked with these strange paths to nowhere, or rather paths to the past.

      The good Reverend Wigram had not made up the names of Great and Little Pepsells after all, so perhaps no one had invented the tree either. The boundary between them was a real place and you could visit it still. There may even be something in the rest of the tale, if once again we allow the logic of that rustic who would not have believed a word of Shonks’ tale if he hadn’t seen the place in the wall with his own eyes. There was certainly a field, so we might as well believe that there was a tree, but what was an ancient yew of all trees doing growing there astride a track in the middle of nowhere?

      A single yew alone outside a churchyard is a great rarity – with or without a dragon’s lair. Of the 311 ancient yews known in Britain, very few are not – and have never been – associated with a known church or religious site, and an ancient yew growing anywhere at all is an unfamiliar sight in the countryside around the Pelhams: there are none in Cambridgeshire, Essex or Bedfordshire, and just two surviving ancient yews known in Hertfordshire – both in churchyards. There are a further seven veteran yews in the county – that is trees between 500 and 1,200 years old according to the latest classification by the Ancient Yew Group – but they are all linked to a church.

      The nearest non-churchyard yew is a lone veteran growing in Hatfield Forest some sixteen miles away. Although Oliver Rackham insisted that it was only 230 years old, ‘and should be remembered by anyone who supposes that big yews must always be of fabulous age’. Recent analysis by an arborist suggests that the tree is much older and has a smaller circumference than you’d expect because it has spent much of its life in the shade. Perched on the edge of the decoy lake, sloughing off the bark of its many-corded bole, it conceals the mysterious cavities of ancient yew. Its existence gives us some confidence that our yew is within the geographical distribution of these curious trees.

      Nearer to the Pelhams, a remarkable specimen lingers in the churchyard of St James the Great, in Thorley, near Bishop’s Stortford. Ringed by precarious gravestones, the main trunk appears to be made from many closely packed smaller trunks, like the product of black fairy magic, an impenetrable palisade of thick stakes imprisoning some secret. A terrible secret: the tree has been hollowed out by arson, its innards gone, and what remains is dreadfully tormented and charcoaled. Yet still it lives and grows and puts out new leaves. Yews are extraordinary trees. In the church is a certificate, from when the Conservation Foundation ran its Yew Tree Campaign in the 1980s, attesting that the tree is 1,000 years old. Ancient yews are now defined as those over 800 years old, with no upper age limit, but determining the age of yews is about as controversial as botany gets. Tim Hills of the Ancient Yew Group writes that the science has moved on a lot since those certificates were awarded based on the ideas of Allen Meredith in his influential The Sacred Yew. Regardless of its age, the yew at Thorley is rightly something to be revered.

      Robert Blair in his eighteenth-century poem ‘The Grave’ calls the yew a cheerless, unsocial plant that loves to spend its time in the midst of skulls and coffins. Illustrating the poem, William Blake depicted the tree’s only merriment as ghosts and shades performing their mystic dance around the trunk under a wan moon, but in his watercolour the tree is at the centre, it is evergreen and blue, not dull, but bright in contrast to the pale spectres encircling it; a tree, like the burned-out Thorley yew, that defies death.

      There are many theories as to why yews are found in churchyards, ranging from the prosaic (useful shelter from the storm) to the poetic (yews were symbolic of the journey to the underworld). The church guidebook to St James the Great lists other reasons: as a symbol of immortality, to stop villagers allowing their cattle to stray into the graveyard (its leaves are poisonous), or because Edward I decreed that yews be planted to protect churches from storms. Wherever they grow, it is generally assumed that their siting has some significance, if only because they must have been preserved from the needs of longbow production for some special reason (by the late sixteenth century, Europe had been almost completely denuded of yew wood). Although others have argued that they were planted in churchyards precisely because they were needed for longbow production and they would be protected from livestock. John Brand, the eighteenth-century compiler of superstitions thought this was nonsense, approving instead of Sir Thomas Browne’s conjecture ‘that the planting of yew trees, in Churchyards, seems to derive its origin from the ancient funeral rites, in which, from its perpetual verdure, it was used as an emblem of the resurrection’. Yews are not accidental trees, they mark things, they remember things: wells or springs, boundaries, lost settlements, meeting places, pagan religious sites or perhaps even the burial places of people who dropped dead along a pilgrimage route. What did the Pelham tree mark on its lonely boundary between two fields?

      Was it originally planted to mark the site of an early Christian saint’s cells? In about 940 the Welsh King Hywel Dda threatened a fine of sixty sheep for felling yews associated with saints. Or did people gather around the yew long ago? Surviving lone trees may have been moot trees – meeting trees – like the Ankerwycke Yew at Runnymede where King John might have signed Magna Carta, and Henry VIII was said to have met Anne Boleyn for the first time. From Anglo-Saxon times until the modern period many southern and Midlands counties were divided into Hundreds, which took their names from the original moots or meeting places of the Hundred Court. Such places were often marked by a significant tree or stone. The Pelhams were in the Edwinstree Hundred – literally Edwin’s Tree – and early records indicate that the meeting place was somewhere in the Pelhams. Place-name historians have guessed that Meeting Field housed the tree, although that name appears for the first time in the late nineteenth century. Great Pepsells was much closer to the centre of the Hundred, bounded by three parishes and fed by ancient paths and trackways. Was Edwin’s Tree a venerable old yew? One early medieval source links Edwin’s Tree to woodland, and woodland may hide the reason for a lone Hertfordshire yew and that track to nowhere.

      At the turn of the nineteenth century, villagers across Essex and Hertfordshire were warned not to be startled by strange lights on the horizon. The engineers of the Ordnance Survey were at large, hauling Ramsden’s immense horse-drawn theodolite from village to village, along with their 100-foot steel chains, twenty-foot high white flags, and their brand-new draught-proof white lights. This was the earliest of the surveys made some eighty years before the large-scale 25-inch with its individual trees. The maps would be plotted at just 1 inch to the mile, but it was a revolution in cartography.

      There are remarkable preliminary pencil drawings, made at a larger scale than the published sheets. The fields seem to stand out from the paper in relief, like anatomical specimens in cross section, finely hachured to look more like a coral reef than rural Hertfordshire. Zoom in and the map covering Great Pepsells is heavily shadowed as if seen through storm clouds, the gathering clouds of the Peninsular War perhaps, which hurried the surveyor’s hand. The field boundaries, which would disappear from the published version, are clearly drawn in, and the house and settlements picked out brightly in red ink. Right in the centre of the drawing between the little red dots labelled Johns Pelham and Lily End is Hormead Park Wood, the woodland that adjoins the south-west corner of Great Pepsells. But it is much larger on the 1 inch than it is today. Instead of the tidy rectangle of later maps, the wood meanders across the fields of Furneux Pelham drawing a shape far more typical of an original ancient woodland boundary.