Caloplaca flavorubescens

Description & Identification

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.


Similar Species

 C. flavovirescens has smaller, darker apothecia which lack oil droplets in the hypothecium.


On wayside and parkland Fraxinus, particularly in limestone areas, and Populus tremula in the Scottish Highlands.


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

"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).

Proposed Actions

UK BAP Signposting actions:

  1. 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.
  2. 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.
Hectad Distribution in Wales/Link to full BLS map

Caloplaca flavorubescens

NBN Taxon Key