Acrocordia conoidea

REACTIONS

K-

DESCRIPTION

Acrocordia conoidea is a crust-like lichen that grows tightly attached to hard limestone. When young, the thallus often shows a subtle pinkish tinge, which fades to pale grey or greenish as it ages. It forms smooth, flat patches that can easily blend into the rock surface, so it can be easy to overlook at first.

The most distinctive feature is the presence of tiny black dots, the fruiting bodies called perithecia, which often sit in shallow pits and can look like miniature cones or volcanoes. These are usually best seen with a hand lens. The combination of the pale or pinkish crust with the small black perithecia is the easiest way to identify this species in the field.

A useful tip for beginners is to check exposed limestone surfaces in upland areas or quarries for pale patches with tiny black “pimples.” Seeing the pinkish young thallus is a helpful clue that you’ve found Acrocordia conoidea rather than a similar-looking grey crust.

HABITAT

Acrocordia conoidea grows on hard, exposed limestone, often in upland areas, quarries, or natural limestone outcrops. In North Wales, it favours clean, well-lit sites where the rock surface is relatively stable and free from soil or heavy moss cover. It thrives in areas with good air quality and moderate moisture, such as lightly shaded ledges or cliff faces, but it is hardy enough to tolerate sunny, exposed conditions as long as the limestone remains intact.

STATUS IN NORTH WALES

Uncommon but locally frequent

This species is not widespread, but where suitable limestone occurs it can be locally abundant. Because it is small and easily overlooked, it is probably under-recorded in many parts of North Wales.