Lichens : Peltigerales : CollemataceaeLichens

Lathagrium fuscovirens (With.) Otálora, P.M.Jørg. & Wedin

Description: This rather leathery, dark olive green to black, foliose ‘jelly lichen’ is particularly characteristic of hard, dry, natural limestone surfaces. The thallus (to about 5cm diam.), is deeply lobed and channelled and hardly swollen when wetted, which is unusual for species of this genus. Small isidia which form on the surface of the lobes, give the lichen a scurfy appearance. It is common on both dry stone walls and rock outcrops in limestone areas of Ireland.

Key Identification Features:

  • It is most likely to be confused with Collema auriforme, which has larger, more rounded isidia
  • It is best adapted to the hard Carboniferous limestones of the west of Ireland.

Original text submitted by Simon Davey

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

iNaturalist: Lathagrium fuscovirens at iNaturalist World Species Observations database.

 Giavarini, Vince J., Simms, Michael J., & Davey, Simon, 2026. Lathagrium fuscovirens. (With.) Otálora, P.M.Jørg. & Wedin. [In] Lichen Ireland.
https://www.habitas.org.uk/lichenireland/species.php?item=18443. Accessed on 2026-11-12.