Caloplaca lucifuga
Found on bark with inconspicuous thallus - immersed in the bark or as a thin grey film. Soralia are numerous and very crowded, often contiguous, pale yellow to dirty yellow-orange-brown, flat and ulcer-like bcoming convex and rounded; soredia farinose (floury). Apothecia are unknown. Chemistry: Thallus K-, soralia K+ purple Ray Woods says: This is a very obscure species first described in 1988. It appears as a khaki/gold smear that is K+purple. I have had immense difficulty refinding it in a number of sites.
Photo: V. Alstrup
Caloplaca ulcerosa and C. obscurella are similar but have more scattered and discrete soralia which are K-.
In crevices of rough bark of old trees, especially oak, in wood-pasture. In the the Welsh Marches it is found deep down in crevices in the bark of ancient oak trees usually in well-lit situations. The old deer parks and ornamental parklands of the March suit it well. (RGW)
W. Europe. Herefordshire, N. Devon, Northumberland, S. Scotland. Mid-Wales. Its world headquarters appears to be the Welsh Marches. (RGW)
Records from Wales
| Location | Grid Reference | Last Rec'd | Recorders(s) | SSSI |
| Brecknock: South of Trefeinion, Llangorse | SO13372946 | 2003 | R.G. Woods | |
| Brecknock: Pwll-y-Wrach, valley S of Talgarth | SO163325 | 1989 | R.G. Woods | |
| Brecknock: North of Llysdinam | SN998599 | 2009 | R.G. Woods | |
| Ceredigion: Nanteos Mansion Park | SN616780 | 1992 | R.G. Woods | |
| Ceredigion: Trawscoed | SN670733 | 1996 | S.P. Chambers | |
| Meirionydd: Corwen Rug | SJ058445 | 1996 | A.O. Orange | |
| Radnor: Maesllwch - Castle Park | SO1640 | 2003 | S.P. Chambers | |
| Radnor: N of Pencerreg | SO044540 | 1997 | R.G. Woods |
The following notes are from Ray Woods:
South of Trefeinion, Llangorse - on a tree in lane bank.
North of LLysdinam - on a tree in pasture woodland.
- Monitor the habitat and species at sites, at least every 6 years, to ensure that owners and occupiers continue to be aware of the presence of this lichen and that management maintains and/or expands suitable well-lit mature and veteran native trees, paying special attention to threats from excessive shade cast by climbers and evergreen trees and shrubs, particularly invasive non-native species and inappropriate grazing levels, forestry operations or adjacent land uses. Enusure wayside trees are kept free of fertilizers, manure and slurry through the implimentation of agri-environment schemes.
- Promote further survey of potentially suitable trees and bring any newly discovered populations into the monitoring/management programme.
- Encourage the planting of new suitable wayside, hedgerow and parkland trees to provide additional habitat and the promotion of existing trees towards veteran status.
Coppins, B.J & Fletcher,A. (2001). Caloplaca lucifuga. Species account 1642/2001 in the Caloplaca fascicle of the Lichen Atlas of the British Isles produced by the British Lichen Society, London.