A leprose lichen which ranges from bright green to yellow-green to sulphur yellow in colour. Generally powder thin, but can be thicker in places which cracks. Apothecia rare.
Found in sheltered, dry places on sandstone rock overhangs, dry-stone walls and on man-made stone or brick. Rarely found on bark. Common and widespread throughout Britain.
Photographs of Sulphur Dust Lichen (Psilolechia lucida), taken February 2012 on local Bunter Sandstone outcrop, Staffordshire. © Pete Hillman 2012. Camera used Panasonic Lumix DMC-FZ38.