This moisture-loving lichen is native to Europe and North America, especially in cooler climates, but it is found in arctic habitats and even, occasionally, in rainforests. It grows on peat, rotting logs, humus, turf, clay, dead mosses, in shaded areas. In addition to the common names listed, “fairy puke” is among several that are less charming.
Identification: The lichen is crustose, looking a bit like spilled paint, thinly coating its substrate with a greenish-grayish (often described as mint green), granular surface.
Fruits: Fruiting bodies, or apothecia, as they are called in lichens, are pinkish, pale orange, or brownish, and ¹/₃₂-⅛" (1.5-4 mm) in diameter. They are rounded, and wrinkled, a bit like brains. They are often in clusters. They look a bit like tiny mushroom caps. They are usually stalkless, but may have short stalks.
These are closely similar:
Icmadophila ericetorum at Alan Silverside's Lichen Pages on LastDragon.org
Icmadophila ericetorum on botanyphoto.botanicalgarden.ubc.ca
Icmadophila ericetorum on www.centralcoastbiodiversity.org
Icmadophila ericetorum on lichenportal.org
Icmadophila ericetorum description by Thomas H. Kent, last updated 2 Jan 2021.