Schismatomma graphidioides

This is a supper iPhone/Lichen Candelaris picture I took on Eastern Friday of Schismatomma graphidioides:

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Schismatomma graphidioides on Beech, Ferny Crofts, New Forest

This is a rare species, which can turning up in sheltered field trees, or similar trees in landscape parks, in sites that are not that outstanding for lichens, as well as in richer pasture woodland sites. It can also occur on all sorts of trees; it is quite unpredictable in its occurrence, one just finds it, rather being able to target it. I am finding it much more in the New Forest in the last few years, on Sallow, Beech, Holly, Sweet Chestnut and Ash, but I have no idea if it is increasing or if I have just got better at spotting it. It can have a close resemblance to the now very appropriately named Pseudoschismatomma rufescens (was Opegrapha rufescens) and this increases the difficulty in spotting it, both have lirellate apothecia with a rim of paler thallus around the apothecia on a brown thallus.

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Pseudoschismatomma rufescens & Opegrapha vulgata, on Ash, Ballykeefe Nature Reserve, Co. Kilkenny, Ireland

The best field feature for the most similar Schismatomma graphidioides thalli (like mine) is that the lirellae are much more likely to be branched to stellate, compared to Pseudoschismatomma rufescens. However, it is always best to check an apothecia section (as I did). All the numerous, but sometime subtle differences, are listed by Steve Chambers at http://wales-lichens.org.uk/species-account/schismatomma-graphidioides” class=”bbcode_url”>http://wales-lichens.org.uk/species-account/schismatomma-graphidioides. The most distictive differences are the absence of a true exciple and the dark brown-black; K+ deep green-black hypothecium in Schismatomma graphidioides, as opposed to the narrow, thin, persistent and dark true exciple and the chestnut brown, K- hypothecium in Pseudoschismatomma rufescens.