Thallus a diffuse, rather thick, powdery crust, pale to greenish blue-grey, with a white medulla, granules commonly with a weft of projecting cottony hyphae.

On rocks, walls and tree-trunks, especially where sheltered from direct rain.

All year round.

Widespread and evidently common, including in urban areas, but part of a complex of species that require thin-layer chromatography for certain identification.

Status in Leicestershire and Rutland not known.