Myriotrema glauculum

Spore Ascus

Thin Section

Thallus

Lichen Index

Myriotrema glauculum thallus and apothecia.

As with all Myriotrema lichens, the apothecia are buried in pits within the thallus. The margins of the pits have a double wall. In the case of M. glauculum the inner wall becomes separated from the outer. Also characteristic of this species is the cracked thallus, a condition termed "rimose". The thallus surface becomes yellow in the presence of ultraviolet light.