''Placocarpus schaereri'' is a species of

saxicolous A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, give ...

(rock-dwelling),

areolate Lichens are composite organisms made up of multiple species: a fungal partner, one or more photosynthetic partners, and sometimes a basidiomycete yeast. They are regularly grouped by their external appearance – a characteristic known as their ...

, and

crustose lichen Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichen ...

in the family

Verrucariaceae The Verrucariaceae are a family of mostly lichenised fungi in the order Verrucariales. The lichen-forming species, which comprise the vast majority of the family, have a wide variety of thallus forms, and include crustose (crust-like), foliose ( ...

. Found in Europe, it is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of genus ''

Placocarpus ''Placocarpus'' is a genus of lichens in the family Verrucariaceae. The genus was circumscribed by Italian botanist Vittore Benedetto Antonio Trevisan de Saint-Léon Vittore Benedetto Antonio Trevisan de Saint-Léon (5 June 1818, in Padua &nd ...

''. The lichen was first described scientifically in 1831 by

Elias Magnus Fries Elias Magnus Fries (15 August 1794 – 8 February 1878) was a Swedish mycologist and botanist. Career Fries was born at Femsjö (Hylte Municipality), Småland, the son of the pastor there. He attended school in Växjö. He acquired ...

, who called it ''Parmelia schaereri''. The species epithet honours Swiss pastor and lichenologist

Ludwig Schaerer Ludwig Emanuel Schaerer (11 June 1785 – 3 February 1853) was a Swiss pastor and lichenologist. Interested in natural history from a young age, Schaerer trained as a teacher and studied theology in Bern. During his career as a teacher, orph ...

. Othmar Breuss transferred it to the newly reinstated genus ''

'' in 1985. Juvenile forms of ''Placocarpus schaereri'' are often

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has c ...

on the lichen '' Protoparmeliopsis muralis''.

References

{{Taxonbar, from=Q10632548 Verrucariales Lichen species Lichens described in 1831 Lichens of Europe Lichenicolous lichens Taxa named by Elias Magnus Fries