Description: This rarity is a member of the dry bark community of lichens that colonises the slightly nutrient-enriched bark of old deciduous trees growing in glades or near the boundaries of former estate parklands. It has a thin, cracked, whitish-grey, non-sorediate thallus with numerous, black, irregularly-shaped discs. The species was originally described in the nineteenth century from material collected in Dublin. While now presumed extinct in Ireland, this is an excellent time to search for it on ash, beech or oak.

Key Identification Features:

• Grows on the old, dry bark of mature deciduous trees; thallus white to grey, cracked, supporting numerous black discs, very irregular in shape
• It is non-sorediate and Pd-.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Schismatomma ricasolii at iNaturalist World Species Observations database.