Luxuriant growth of a lichen in a hedge in the Tunstall valley

 A leafless hawthorn hedge in the Tnstall valley, County Durham, shorn with geometric precision by a tractor-mounted hedge cutter, but decorated with one of the most luxuriant arrays of lichens I’ve ever seen. Much of the hedge was bare, apart from scattered yellow encrustations of common orange lichen Xanthoria parietina, but short lengths were festooned, like overdressed Christmas trees, with countless dangling fronds of farinose cartilage lichen Ramalina farinacea.

This valley offers high quality lichen habitat, thanks to relatively unpolluted North Pennine winds and humidity from Tunstall reservoir, but why had these short lengths of hedge become so gloriously laden with this particular species? I recalled walking here last summer and finding the same sections defoliated by small ermine moth caterpillars that had sheathed twigs in their silken web. By autumn the hedge had begun to recover, but maybe that leaf-loss and interruption in twig growth had given wind-blown lichen spores sufficient opportunity to colonise bare twigs, trapped by that web of sticky silk? It’s tempting to believe that the beauty of this winter hedgerow was due to the arrival of an egg-laying female ermine moth last spring, a serendipitous event in the endless, unpredictable cycle of life.

Danish scurvy-grass Cochlearia danica

 

Seen on my walk into town this morning - an exquisite rain-glossed rosette of fresh, spoon-shaped succulent leaves of Danish scurvy-grass Cochlearia danica, growing in the grime that accumulated between a wall and the pavement.

It’s a seaside native wild flower that thrives in salt spray on clifftops and sea walls along the north east coast; here, an hour’s drive inland, it’s doused in saline mist that hangs in the slipstream of traffic, along roads treated with de-icing salt in winter.

When we first moved to the north east, 50 years ago, it was confined to the coast but since then Danish scurvy-grass has followed salt-spreading council vehicles inland, all the way into the North Pennines. In another month a ribbon of its tiny white flowers will decorate road verges along most of our major roads, followed by a prolific crop of tiny seeds that will be carried away on car tyres.

Cochlearia danica is member of the cabbage family. Scurvy-grass leaves have a high vitamin C content and have been used as a fresh green vegetable and to ward off scurvy, but were described by C. Pierpoint Johnson in his Useful Plants of Great Britain: a Treatise, published in 1863, as ‘scarcely superior to water-cress in medicinal effect and much less palatable’ although ‘well known to the early navigators as a remedy for the terrible disease that formerly decimated our ships’ crews on long voyages and was brought much into the notice at a somewhat later period by the use to which it, with other like herbs, was applied by Captain Cook in his expeditions to the Southern Seas.’

Scurvy-grass flowering on Craster harbour wall, on the Northumberland coast, in spring.

Winter gnats lekking on a winter afternoon.

 A freezing cold afternoon, but a swarm of these winter gnats Trichocera sp. was dancing, in a shape-shifting column, above the garden hedge this afternoon, catching the last rays of sunlight as the sun was sinking towards the western horizon. They would have all been males, lekking, attempting to catch the attention of a female.

The flower border beside the hedge is covered in a thick layer of decaying autumn leaves - just the kind of place where the females will lay their eggs.

There are come close-up pictures of winter gnats here