Caloplaca flavorubescens
Description
This species has a white to yellow-green thallus, smooth, continuous and uncracked, coarsely granular-papillate. Apothecia are up to 3mm diam., with a bright orange disc, scattered to crowded, rounded, usually flat. the lower part of the hymenium and hypothecium have numerous oil droplets. It forms irregular patches between other lichens on bark.

Photo: www.toyen.uio.no
Similar Species
C. flavovirescens has smaller, darker apothecia which lack oil droplets in the hypothecium.
Habitats
On wayside and parkland Fraxinus, particularly in limestone areas, and Populus tremula in the Scottish Highlands.
Distribution
Europe, Macaronesia, N&S America. Asia, Africa, Australia. Lowland England, Scotland & Ireland. N. Wales.
Records from Wales
| Location | Grid Reference | Last Rec'd | Recorder(s) | SSSI |
| Anglesey: near Friars, Beaumaris-Penmon | SN 68* | 1895 | J.E. Griffiths | Yes? |
| Caernarfon: Glynllifon Park | SH 45 | 1971 | F. Rose | Yes? |
Notes on Individual Locations in Wales
"near Friars, Beaumaris-Penmon": Friars or Fryars is the old Franciscan monastery adjacent to Baron Hill Park SSSI at SH609774 (note * if this is the case the hectad given for the record - SH 68 - is incorrect). Friars adjoins Baron Hill Park SSSI and this is the most likely location for the C. flavorubescens record. Baron Hill was surveyed for lichens by William Purvis and Peter James in 2003, with some follow-up work by Ray Woods. C. flavorubescens was not found, and the lichen flora generally was deemed to have declined in quality. (The site was also surveyed by Alan Orange in 1996 as part of the CCW Welsh Parklands Survey - Alan considered there was little evidence of decline at this stage).
Glynllifon Park: Much of the site is SSSI (centroid grid reference SH 456 550) though the exact location for this record is not clear. (Recorded as on old Fraxinus).
Hectad Distribution in Wales/NBN Gateway Map
(Be aware that the data on the Gateway may be incomplete and the maps should not therefore be relied upon as a full representation of the distribution of this species. Note that the maps coverage includes some parts of England. Also, without a registered account on the Gateway your access to datasets may be limited)
Proposed Actions
UK BAP Signposting actions:
- Encourage the planting / replacement of pasture and wayside Ash trees to ensure continuity of suitable habitat. Ensure the trees are kept free of scrub and ivy.
- Re-survey all sites to establish presence/absence of the species. Enusure wayside trees are kept free of fertilizers, manure and slurry through the implimentation of agri-environment schemes.