Lichens : Caliciales : CaliciaceaeLichens

Diplotomma pharcidium (Ach.) M. Choisy 

Description: This epiphytic member of the genus has recently been found in Ireland (Westmeath). Like D. alboatrum (described elsewhere), it has submuriform spores but unlike that species, possesses a conspicuous rim or exciple around the large flat disc. Examination of the spores shows that longitudinal divisions occur immediately to either side of the septum. Smooth nutrient-rich bark.

Key Identification Features:

  • On smooth nutrient-rich bark such as ash, poplar, willow; slightly frosted disc with distinctive exciple not unlike that of Buellia disciformis
  • Spores with longitudinal divisions either side of the septum.

Original text submitted by Vince J. Giavarini

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

iNaturalist: Diplotomma pharcidium at iNaturalist World Species Observations database.

 Giavarini, Vince J., Simms, Michael J., & Davey, Simon, 2026. Diplotomma pharcidium. (Ach.) M. Choisy . [In] Lichen Ireland.
https://www.habitas.org.uk/lichenireland/species.php?item=500036. Accessed on 2026-11-12.