A home for nesting birds and rare butterflies, but is it good or evil?

Aptly named due to its black bark, this dense and very prickly shrub manages to smother itself with flowers some time before its leaves appear. Somehow, it also anticipates the presence of insects because it depends upon them for pollination of its blossom. It does not rely upon the wind in the manner of hazel catkins; they produce their pollen rather earlier.

The blackthorn can burst into flower as early as March, but this month appears to be its favourite; indeed, it is one of the signs that spring has truly arrived, even if there are times its blossom is covered in snow or struggling to cope with overnight frosts. From time to time, one hears the phrase "blackthorn winter". This is a period of the spring which is often dominated by extremely chilly east winds, which seem to arrive when the blackthorn is in flower.

The shrub, which grows to a height of about 12ft (4m or so), has many benefits. Perhaps the best known is that its branches grow very close together, often entangling themselves, and are covered with long, very sharp spikes. This makes it a superb barrier and, when several specimens grow together to form a thicket, they create an impenetrable hedge. Not only do they protect other plants growing beneath, they also provide excellent cover for nesting birds.

Another blackthorn bonus is the fruit it produces. These are sloes, small round purple-black plums with a beautiful bloom to their skins. Although they are probably ancestors of our domestic and far sweeter plums, sloes are intensely bitter to the taste. Given the right treatment, however, they can be made into a wonderful liqueur called sloe gin, or other treats like home-made wine and even jam. Near my home, they are used to flavour some beautiful chocolate.

Collecting sloes is never easy due to all those spikes and it's a good idea to wear stout gloves. Like other hedgerow fruits, they mature in the autumn, and it is thought that our Stone Age ancestors used them for making dyes.

Because the branches and twigs are generally very short, the blackthorn's wood has few commercial uses in spite of its toughness. The teeth of wooden rakes are sometimes made from this wood and I believe the timber is also used in marquetry. Perhaps its best known use is in the creation of short and ornamental twisted walking sticks and the famous Irish weapon or club called the shillelagh.

Not surprisingly, the blackthorn has produced a few superstitions. In medieval times, it was variously regarded as both a holy tree and a symbol of evil.

Its links with evil came from the black colouring of its bark, while its white blossom on leafless branches produced its holy image in some areas. In a few districts, it was thought to flower on Christmas Eve and another belief was that Christ's crown of thorns was fashioned from its twigs. In some parts of England, crowns of thorns were made from its twigs and then burnt, in some cases with their ashes being scattered over corn fields to ensure a good crop later in the year.

I believe it is quite common for people not to bring blackthorn flowers into the house because it is considered unlucky to do so, and in some past cases it was regarded as an omen of death if it was taken into the home. In Hertfordshire, however, a crown of thorns was made from blackthorn wood on New Year's morning and then held over the fire until it was scorched. It was then hung up with the mistletoe and, in this case, was thought to be a bringer of good fortune. And finally, another useful aspect of the blackthorn. It is a favourite nesting site for the charming and very rare black hairstreak butterfly. The eggs are laid on sloe twigs during the summer and remain there during the winter.

When the caterpillars hatch in the spring, they feed on the flowers and buds of the blackthorn. When a caterpillar becomes a chrysalis, it clings to a twig where it resembles a bird dropping - a very good camouflage.

But the chance of finding these butterflies in this region is almost nil - they are to be found only in the east Midlands and then only in a very few colonies which may still exist.

On the topic of bushes and shrubs being used as barriers, I have come across a story concerning an old church in a very isolated part of this region.

It was in the Forest of Lunds, which is a remote area in the high Pennines above Hawes and Cotterdale, almost in the shadow of Great Shunner Fell. Wensleydale's River Ure has its tiny source on Lunds Fell, from where it flows down the width of Wensleydale. Now, I believe the area is known simply as Lunds.

So far as I know, there has never been a village called Lund on this site, although the area was occupied by widespread and very remote farmsteads. Lund is an old Scandinavian word meaning a wood or forest and, in the past, this part of the moor was covered with trees, probably the more hardy ones such as rowan, birch, oak, ash and blackthorn.

As they were consumed for building construction or perhaps fuel for heating and cooking in those remote homes, so the land would eventually revert to a deserted plateau. That happened with lots of northern moors.

In Yorkshire, there are other places bearing the name Lund. The name crops up in several places around Malton, for example, and there was also a Forest of Lund near Pickering which seems to have disappeared during the 14th century.

The name has given rise to a similar name, Lound, which in turn has produced names like Loundsdale or Loundale, perhaps with Lonsdale being derived from it. In the dialect of the North Riding, the adjective lound refers to somewhere which is calm, still and sheltered, and that fits well with the atmosphere of a peaceful woodland.

However, the story concerns an old church which served as a focus for the community which lived on the remote heights of Lunds at the head of Wensleydale. As there was no village, the church was the centrepiece for the local farmers, just as other churches in remote areas provided community assembly points.

Lund church was a tiny stone building with a thatched roof and I believe its remains can still be seen close to a stream not far from the famous Moorcock Inn.

However, the church had no door and there is one story of a preacher arriving to find several inches of snow on the floor inside.

But not having a door meant the church was open to the livestock which freely roamed those heights, so it was protected by a substantial thorn bush which had to be placed in the opening. I rather suspect it was a blackthorn, but it was understood by the congregation that "t'last yan oot puts t'bush in t'hole."

Among my correspondence this week is a note from the British Trust for Ornithology (BTO) which praises farmers and landowners for their efforts in protecting endangered species of wild birds. This has been achieved by allowing cereal fields to remain as stubble during the winter months and it has had a marked effect upon yellowhammers and skylarks.

There has been a noticeable increase in their breeding numbers in areas where stubble has been allowed to remain. If the area of stubble left unploughed until the spring on lowland farms can be increased from the present 3pc to 10pc, this should be sufficient to halt the decline over the breeding season.

It is further claimed that raising this amount to 20pc will actually produce an increase in bird numbers.

Although the yellowhammer and skylark have been particular beneficiaries from this development, it has been noted that other seed-eating birds also benefit from winter stubble.

Another note has come from the Rothamstead Research Institute to say that, while we think butterflies flutter at random, they are in fact following well-defined routes as they go about their nectar-gathering routine.

Tiny radar transponders, a fraction of their body weight, were fitted by researchers to tortoiseshell and peacock butterflies. This allowed them to monitor their flights