Stereocaulaceae Lepraria nivalis Growth type leprose Chemical results: K+ yellow, C-, P+ red, UV- Can be locally abundant on hard calcareous rocks where sheltered from rain and direct sunlight and in caves and underhangs. The soft, thick thallus is white or very pale blue-grey with a weakly-lobed margin and cottony medulla. Sometimes with very sparse brown hyphae on the underside. Well-developed thalli can be be peeled off the substrate. Similar: Lepraria vouauxii is K+ dirty yellow to orange, C+ dirty yellow

Lepraria nivalis
On limestone. Portland, Dorset. February 2016