ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Lecanoracea

Genus Lecanora, meaning 'beautiful small bowl' - from the shape of the apothecia

Common name:            Members of the genus are collectively known as 'rim lichens'

Synonym:                    -          

Primary habitat:            Woodland, wayside trees, fences and posts

Usual substrata:            Bark, or worked wood

Growth form:                Corticolous, lignicolous

Thallus:                  Crustose

Apothecia:                    Lecanorine

BLS identity rating:        2/5 (visual identification relatively easy with care)

Thallus variable, but roughly circular, usually forming neat delimited patches from 3-12cm across; relatively thick, smooth to roughened or slightly warty, sometimes areolate; typically, pale grey, although sometimes creamy to yellow-grey; prothallus white, but not always conspicuous with some authors describing as absent.

Apothecia numerous, often tightly packed, at least in part; up to about 1mm dia., occasionally a little larger; disc colour variable, effectively two morphs; the lighter of which ranges from dull brown to rose-brown or orange brown; the darker, red-brown or chestnut-brown; turning jade-green when wet; only rarely slightly pruinose; persistent and well-developed, smooth or slightly crenulate, occasionally distorted when grouped; thalline margin near enough concolourous with the thallus 

Lecanora chlarotera will most likely be found on deciduous trees either in woodland or alongside paths and tracks in more exposed locations. Both colour morphs can occur on trunks but, on branches and twigs, it is more likely to be the darker form.

This species is covered in slightly more detail in the woodland section.

The specimen feature here was part of a community photographed on a wayside ash tree in Austria, situated between the large Physcia aipolia and the bright yellow patch of Xanthoria parietina - other lichens include Phaesophyscia ciliata, Caloplaca cerina, Physcia tenella or adscendens and Candelariella sp as kindly identified by someone who is familiar with these species.