Description: Formerly named L. xanthostoma or L. flotowiana this lichen which belongs to the L. dispersa complex, has a dirty dark-grey to black endolithic (immersed) thallus and slightly frosted grey-brown discs with a thick, faintly notched white disc margin. It grows on calcareous rocks. All candidate discs should be spot tested, especially the disc margins which in this species react K+ yellow, UV+ yellow to bright orange. In Ireland, the species is present in central and southern regions.

Key Identification Features:

• Near black thallus sprinkled with white-edged pale brown discs which stand out against the background; on hard limestones
• The thick white disc margins test K+ yellow, UV+ yellow to bright orange.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Myriolecis semipallida at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Myriolecis semipallida at iNaturalist World Species Observations database.