Today's gravestones, a headstone and a footstone, both limestone, Eliz. Packwood, 1917. A couple of dozen species, one of which a lichenicolous fungus.
Thread:
Plus Verrucaria polysticta on the footstone. 10/24 are members of the Verrucariaceae. C. dichroa described as new in 2006. V. obfuscans added to British list in 2015.
Three lichens, all common on the headstone, none of which would have been named correctly (or at all) twenty years ago. Caloplaca dichroa and Verrucaria ochrostoma on left side. But what about the ashy grey expanse on the right?
I kept coming across these grey thalli on old limestone memorials, often with pinkish dots which proved to be sterile plugs of tissue, and despaired of ever finding out what they were. Eventually I started to find some fertile examples...
A thread about Thelidium pyrenophorum:
Verrucaria nigrescens, T. pyrenophorum and, on left side, one of the species that redeposits calcite to form a moderately well-developed lithocortex. Microscopy showed this one to be Thelidium decipiens.
Verrucaria nigrescens (dark brown) and V. obfuscans on right side and forming a peninsula projecting into the nigrescens. V. obfuscans is common in churchyards but not recognised in Britain before 2015.
V. obfuscans, V. nigrescens (and Caloplaca flavescens).
Verrucaria obfuscans:
Verrucaria polysticta on the footstone.
This rather unremarkable ash tree close by has a more interesting lichen community than one would expect, partly influenced by colonisation from old gravestones. It is the only tree in the parish to support Bacidia rubella.
Presumably the B. rubella colonised the ash tree from one of the old gravestones.
The ash tree also has an extensive colony of Caloplaca ulcerosa:
...and Pseudoschismatomma (Opegrapha) rufescens:
...and Piccolia ochrophora.
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