Gregorella humida (Kullh.) Lumbsch

A pioneer crustose microlichen with a finely granulose thallus, containing cyanobacteria from the Nostoc genus. It grows on acidic, disturbed or recently exposed, humid, less permeable sandy or clay soils. The lichen may resemble the rare Fuscoparmelia nebulosa by the dark, granulose thallus. However, the two species are well recognisable in the sterile stage under a microscope thanks to the compact crust on the goniocyst surface of G. humida. Leptogium byssinum is another species with a similar ecology and similar morphology in the sterile stage.

Gregorella humida is usually found in anthropogenic habitats, such as sand pits, quarries, trenches, road and railway notches. It is expected to naturally occur in humid, eroding slopes, in alluvia of watercourses, etc. There are no historical reports on this taxon and no older specimens have been found during the herbaria revision (Vondrák et al. 2013). In the past, the species was rather overlooked, since its thalli may resemble cyanobacterial films and fruiting bodies are often missing. It is a typical pioneer lichen (Poelt & Vězda 1990) that appears suddenly during the succession and soon disappears again. It is scattered to rare in the Czech Republic, distributed mainly from middle to lower mountain elevations.

Literature: Poelt J. & Vězda A. (1990): Über kurzlebige Flechten – (on shortliving lichens). – Bibliotheca Lichenologica 38: 377–394. Vondrák J., Palice Z., Mareš J. & Kocourková J. (2013): Two superficially similar lichen crusts, Gregorella humida and Moelleropsis nebulosa, and a description of the new lichenicolous fungus Llimoniella gregorellae. – Herzogia 26: 31–48.

taxonomic classification:

Ascomycota Lecanoromycetes Arctomiales Arctomiaceae Gregorella

Red List (Malíček 2023):C3 – endangered

Occurrence in the Czech Republic

All records: 19, confirmed 17. One click on a selected square displays particular record(s), including their source(s).


record after the selected year
record before the selected year
records without date
Doubtful and erroneous records are not displayed.
credible record
doubtful record
erroneous record
record without revision

Altitude preferences

Distribution Timeline

Substrate type

Substrate preferences

© Botanický ústav AV ČR, v. v. i. 2020–2024