Colourful mix of lichens

[Bruce Williams]

Stony Stratford, Bucks. On west facing concrete wall.

Help with identification appreciated:



Bruce

[AlanS]

OK, the easy one is Xanthoria parietina, the large, orange, foliose species in the centre.

Towards the top right you have a single, grey apothecium of Aspicilia contorta - this would have been difficult to recognise but it matches well the photograph of the species that you have already posted.

Bottom left, the scattered orange apothecia with little in the way of a thallus appear to be Caloplaca oasis (a recent 'split' of C. holocarpa and not easily distinguished from that species, but apparently the more common of the two on concrete).

The white patches, split into angular units (areoles), each with a developing apothecium, are Lecanora albescens, a common early colonist on concrete.

The scattered yellow apothecia, e,g. on the right of the photograph about halfway down, are either Caloplaca citrina (purple with potassium hydroxide) or a Candelariella species (non reactive with potassium hydroxide). I prefer not to be definite on this one.

Alan

[Bruce Williams]

Tanks for your very comprehensive reply Alan - very much appreciated.

Bruce