Bathelium


Bathelium is a genus of lichen-forming fungi in the family Trypetheliaceae.

Taxonomy

The genus was circumscribed in 1803 by Swedish lichenologist Erik Acharius, with Bathelium mastoideum assigned as the type species.

Description

Genus Bathelium features a thallus usually with olive-green to brownish or greyish hues. This genus is distinguished by the form of its ascomata, the spore-producing structures, which possess apical ostioles. These ascomata can be found either singly or in groups, and often form, a stroma made of both thallus tissue and bits of host tissue. They are noticeable, ranging from to, and show a brown-black colouration, though in rare instances, they may have a whitish appearance. This is complemented by a peripheral layer made up of tightly packed cells.
Within the ascomata, the, a tissue layer containing filamentous structures, is clear and hyaline. It comprises thin, interconnecting filaments known as. The number from one to eight per ascus. They are transversely septate to , with thin septa and more or less angular. These spores are, meaning they have a spindle-like shape, with either acute or rounded ends, and are not constricted at the median septum. They appear hyaline, do not react to iodine, and are encased in a gelatinous sheath.
No conidiomata have been identified in this genus. In terms of chemical properties, Bathelium frequently contains anthraquinones, compounds often present internally in pseudostromata. Lichexanthone, a fluorescent xanthone compound, is occasionally found within the genus.

Species