Lichens : Peltigerales : PannariaceaeLichens

Psoroma hypnorum (Vahl) Gray

Description: Related to Pannaria and easily mistaken for Protopannaria pezizoides, this is an adorable lichen of leached soils in damp, misty places such as below waterfalls and on wet mountain ledges. The small green-grey to almost orange-brown squamules – bright green when wet – intermixed with nodular structures called cephalodia similar in colour to the squamules, form the thallus. Red-brown discs are common, with numerous short hairs below and a chorus of squamules (not granules) attached to the edges. In Ireland, the species is rare; few recent records.

Key Identification Features:

  • • Thallus of small, green (or very bright green if wet) to orange-brown squamules mixed up with squamule-like cephalodia
  • Discs red-brown, hairy below, fringed with squamules; Protopannaria pezizoides has discs edged with granules and a thallus almost black when wet due to the presence of Nostoc (note: Nostoc also turns Collema lichens black).

Original text submitted by Vince J. Giavarini

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

iNaturalist: Psoroma hypnorum at iNaturalist World Species Observations database.

 Giavarini, Vince J., Simms, Michael J., & Davey, Simon, 2026. Psoroma hypnorum. (Vahl) Gray. [In] Lichen Ireland.
https://www.habitas.org.uk/lichenireland/species.php?item=18969. Accessed on 2026-11-12.