ASCOMYCOTA | LECANOROMYCETES > LECANORALES > Lecanoracea

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

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

Synonym:                    -

Primary habitat:            Coastal, but also inland 

Usual substrata:            Rock  

Growth forms:              Saxicolous       

Thallus:                  Crustose                      

Apothecia:                    Lecanorine                  

BLS identity rating:        Graded 2/5 (visual identification possible with care)

Thallus usually circular, to around 10cm dia., can be warty or areolate; dullish white, pale green or grey-greenish, fimbriate although sometime inconspicuous white prothallus; apothecia numerous, usually crowded towards the centre, sessile, up to 1.5mm dia., disc flat to slightly convex, smooth, brown-red to chestnut, often blackish when old, thalline margin white, smooth, but becoming twisted or distorted, with small irregular crystals.

Very common on basic to calcareous substrata, as well as nutrient-enriched acid rocks, both coastal and inland.

I'd like to say that I'm confident that the small specimen I photographed on a little rocky outcrop on Chesil Beach is Lecanora campestris but, unfortunately, I can't. On the other hand, I don't know what other species it could be, so I'm leaving the photo here until I've gained more knowledge to be able to establish whether it's plausible. From what I understand, Lecanora are a difficult group to distinguish, particularly without spot testing and, in some cases, microscopic examination.