Species of the Month - December 2012
Often called the Pepper-pot Lichen but I think it looks more like a dice, with any number from 1-6, or sometimes even more, showing on its top face, and other numbers round the side. This is a common lichen found on many kinds of trees, on both smooth and rough bark, and occasionally on rock too. On the lnhg database we have 5 records on Ash, 3 on Oak, 2 each on Sycamore, Rowan and Birch, 1 each on Beech, Hazel, Alder and Willow and one on an unidentified tree. This suggests it has a preference for trees with alkaline bark but will accept acid ones. We have not yet recorded it on rock.
"fruits" or apothecia of this lichen are black and are immersed in the
warts with just a small area of black showing like a small round dot.
There ae several of these per wart, though a minority of warts have only
The area between the warts
in the Dice Lichen can be
white or pale grey or have a greenish tinge.
Here is the Dice Lichen on Hazel surrounded by the fungus Stereum rugosum and various other lichens.
The species most likely to be confused with P pertusa is P hymenea, which has mostly one apothecium per wart though some warts may have two or three. In P hymenea the visible part of each apothecium is much larger than in P pertusa and is often elongated. There are good pictures of P hymenea at http://www.britishlichens.co.uk/species/Pertusaria%20hymenea%20large.jpg and http://www.habitas.org.uk/lichenireland/photo.asp?item=mjs00597
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15 Dec: we found some on Ash at Dunadd on our lnhg Saturday walk
21 Dec: I spotted some on Ash at Taynuilt
Nov 2012 - Feathered Thorn