Caliciaceae Calicium glaucellum Growth type crustose Chemical results: Thallus K+/- dull yellow Common on lignum of fallen and standing dead trees and on tree stumps, also on fence posts and untreated timber. Short-stalked black apothecia, usually with faint white pruina below head. Thallus very thin, usually immersed. Spores9-13 x 5-6 µm. Pycnidia frequent, conidia 4-5 x 0.8 µm. Photobiont Trebouxia. Micro photo below. Similar: Calicium abietinum has black-brown apothecia, pruina absent. Chaenotheca ferruginea, brownish spore mass, thallus pigment K+ red. Microcalicium spp. have a greenish-black spore mass

Microscope photographs




Calicium glaucellum
On dead trunk. Holton Lee, Dorset. April 2014