Images of British Lichens
Caloplaca "citrina" auct. Brit., name misapplied
Caloplaca aff. austrocitrina Vondrák, Říha, Arup & Søchting
Thallus bright to chrome yellow, forming an irregular, areolate crust, areoles sorediate over much of their surface; apothecia with sorediate margins. Apparently common throughout Britain, including urban areas, on rocks, walls and other artificial substrates such as metal fences. Probably the commonest of a complex of species that includes C. limonia (page pending), C. arcis (page pending), C. dichroa (page pending) and C. flavocitrina.
Refs (for C. citrina, s.l., probably including C. aff. austrocitrina): Arup (2006) (photo); Smith et al. (2009), 259; Purvis et al. (1992), 149; Dobson (2011), 108 (photo); Jahns (1983), 246-247 (photo); Whelan (2011), 58 (photo); van Herk & Aptroot (2004), 90-91 (photo); Thomson (1997), 155; Lichen Atlas of the British Isles 6: 247 (2001). N.B., the brighter orange taxon illustrated in Dobson (2005) under this name is C. dichroa, fide Fletcher & Laundon in Smith et al (op. cit.).
Ref. for C. austrocitrina: Vondrák et al. (2009), 587 (photo), 588.
Recent work (see Powell & Vondrák (2011), British Lichen Society Bulletin 109: 25–27, and (2012), British Lichen Society Bulletin 110: 20–24) has shown that this widespread, typically chrome-yellow species that has been called "C. citrina" is not that species, and it is currently doubtful that true C. citrina occurs in Britain. The identity of British "citrina" is uncertain, but molecular work has shown it matches or is closely related to C. austrocitrina, recently described and known in central and eastern Europe.
If anyone can identify the millipede, please let me know.
|Coastal rocks, Arbroath, Angus, April 2002|
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Uploaded March 2008, last updated February 2013 (first hosted at www-biol.paisley.ac.uk, January 2003)