Prefab Sprout

                                                                                                                                                            Pasque flowers at Therfield Heath photographed by Jo Sinclair

Thousands of purple petals give a nod towards the arable patchwork of Hertfordshire, Cambridgeshire and Bedfordshire. The National Farmers' Union predicts that, for the first time in a decade, the UK will import more wheat this year than it will produce. The farmers where I live appear to be more than making up for it so today I am on a pilgrimage to find native flora beyond the infinite hectares of fat blue-green blades.

The lush Cam Valley is miles behind as we climb a chalky winding path up to Fox Covert at Therfield Heath, Royston. This beechwood nature reserve is managed by the Herts and Middlesex Wildlife Trust. Sun shining through newborn beech leaves is the first treat of the walk. A crooked metal gate leads us out onto the chalk escarpment of a 168m hill, and other pilgrims are here too, lying at odd angles on the slopes pointing cameras at 10, 000 pasque flowers among the short downland grass. About the size of a crocus and a close relative of the anemone, this is a very rare flower, known at only eighteen sites in the UK.

                                                                                   Pasque flower by Jo Sinclair

According to folklore the pasque flower occurs where Roman or Anglo-Saxon blood was spilt. Defence systems such as the Devil's Dyke and Fleam Dyke north of the Icknield Way at Therfield Heath failed to protect the rare plants. Almost all were dug up, disappearing forever. This is a shameful loss as the earthworks were an effective defence against the plough under which 80% of chalk grassland has disappeared over the last sixty years.

Admiring the panoramic view at Therfield I can see the landscape starting to turn yellow as the oil seed rape comes into flower. A red kite soars above the woods. There are random wooden gates without fences dotted across the down. I imagine electric fences are brought in for flocks of sheep to maintain the short turf which is essential for the preservation of a multitude of chalk grassland flowers.

Sheep have done a good job at Magog Down near Cambridge too. On my regular walks I can see a yellow hill a mile off, much softer than the flare of oil seed rape. The chalk grassland here has been managed as a conservation area since the land was acquired in 1989. Yellow cowslip flowers have re-colonised in great profusion. Prosaically they get their name from the old saying that they grow where cowpats have fertilised the soil. A few days ago I walked around Wandlebury and found them thriving there too. It's a triumph to see conservation effective on a relatively large scale like this, but I also relish the fragments of survivors too. I passed a prefab with concrete and chain-link fencing whose lawn was covered in the them.

                                                                                                                                                                        Cowslips at Magog Down Photographed by Jo Sinclair