Calicium adspersum Pers.

A Calicium species characterised by the yellow-pruinose fruiting bodies and the prominent grey thallus that contains norstictic acid (producing red crystals in the reaction with KOH). Like the other species of the genus, it sometimes tends to form an extensive thalli without fruiting bodies (only with black pycnidia). Then care must be taken to the potential confusion with C. salicinum.

Calicium adspersum is an epiphytic species, usually found in furrows of old oak bark, but it grows also on hard wood and on bark of other trees. In the Czech Republic, its distribution overlaps with the distribution of Quercus, it’s the most common substrate. It prefers relic habitats, such as scree margins, rock promontories or old-growth forests. It is a rare lichen, occurring mainly at lower and middle elevations. Exceptionally, it is reported from mountains, such as the Šumava Mts. More common it is for example in the Oslava River valley and in the Brdy Hills. Besides, it is rare, recorded usually only from one or a few trees.

Ascomycota → Lecanoromycetes → Caliciales → Caliciaceae → Calicium