Varicellaria lactea

Varicellaria lactea is a crustose lichen in the family Varicellariaceae. It forms a relatively thick, white to grey‑white, matt crust that breaks into small, tile‑like patches and carries scattered white, powdery soralia (patches that shed tiny propagules); sexual fruiting bodies are rare, and when present they produce a single very large spore, with the lichen containing lecanoric and variolaric acids. Ecologically it is chiefly rock‑dwelling on lime-free siliceous and volcanic rocks in humid, shaded situations, and...