Diploicia

Diploicia is a genus of lichen-forming fungi in the family Caliciaceae. The genus has a widespread distribution, especially in temperate regions, and contains seven species. These lichens form small, tightly attached rosettes with a distinctive pale grey-green colour and a fine, powdery coating that becomes more noticeable when dry. They reproduce through tiny black, pin-prick fruiting bodies that emerge from the crust surface and through powdery outgrowths that can break off and spread the lichen to new locations....read more on Wikipedia.