Cyphelium Ach.
*Account prepared by Dr L. Tibell (Uppsala).
Thallus crustaceous, verrucose to subareolate with small peripheral lobes. Photobiont: Trebouxia. A few species exist as parasymbionts on other lichens. Apothecia sessile or immersed in thallus. Excipulum of variable thickness, blackish-brown and formed of densely interwoven, sclerotized hyphae. Mazaedium well-developed. Asci obovate to cylindrical, always formed singly, dissolving at early stages. Ascospores 1-septate, dark brown, with thick walls. Spore wall often with distinctive ornamentation. Chemistry: Containing β-orcinol depsides and depsidones, and tetronic acid derivatives.
European species are revised by Tibell [ Sv. Bot. Tidskr. 65: 138-164 (1971)]. Cyphelium seems to be a primarily Northern Hemisphere genus and almost all previous records from the Southern Hemisphere are erroneous.
