Unperturbed

While mighty trees
And ancient tombstones
Are felled by winter gales
Fungus and lichen
Sit safe atop the graveyard walls
Unperturbed.

A meander round the village of Chislet in Kent while the rain returned gave me today's unexpected blip. I'd gone in search of moody cemeteries or magnificent trees but it was this that stole the show today. Does anyone know what the fungus is?