ASCOMYCOTA | LECANOROMYCETES > TELOSCHISTALES > Teloschistaceae

Genus Caloplaca, meaning 'beautiful patches'

Common name:            -

Synonym:                      Flavoplaca marina

Habitat:                         Coastal

Substrata:                     Rock

Growth form:                Saxicolous

Thallus:                  Crustose

Apothecia:                    Lecanorine

BLS identity rating:        Graded 1/5 (identification should be relatively straightforward)

Thallus usually in patches up to 5cm across, consisting of small lobules or a cracked areolate crust, yellow-orange to deep orange, margin unclear, occasionally with indistinct short lobes, paler or whitish prothallus, often fragmented and poorly developed; apothecia when present can be numerous, bright orange, to 1mm dia., disc initially flat becoming convex, thalline margin swollen, but narrowing when old, paler and more yellow than the discs.

Common on hard maritime rocks, particularly well-exposed acid rocks, a little less on limestone, occurring from the mesic- supralittoral spray zone upwards. Its appearance is variable, influenced by location, from well-formed to shrivelled and black due to cyanobacteria. In general though, the species can usually be distinguished by its bright orange colour and should not be confused with placodioid species such as Caloplaca thallincola with which it is often mixed, nor with Caloplaca maritima that grows in the upper part of the Caloplaca marina distribution zone, as that species is duller, more yellow, never black due to cyanobacteria, and has brownish wax-yellow rather than orange apothecia discs.