Hi Tiggrx
Yes, confirmation that the Isles of Scilly are a good place to go for these things. I am hoping I might get there myself next year.
So, for what they are worth, my verdicts:
1. Yes, I agree,
Peltigera hymenina is most likely, but without being able to see the characters of the underside (veins, rhizines) this has to be balance of probability rather than a firm ID. The surface is rather dark, but I don't have a better guess.
2. Yes,
Ochrolechia parella. Presumably photographed in shade, hence the blue colour cast.
3. Jenny has already posted the link to my current thoughts on the
Cladonia pyxidata/pocillum group, so I will be brief(ish)! A lot of what is called "
Cladonia pyxidata" is, according to recent Dutch work, really
C. pocillum. However, your photograph shows small, non-imbricated basal squamules and it seems to match my own recent photographs of what I think is true
C. pyxidata (will not go up on my site until I have done more checking), and, more importantly, your photograph also matches the lower photograph in 'Wirth' vol. 1 pg. 307, which the Dutch approve as true
C. pyxidata. [For anyone who has the book, the upper photograph so named on the same page is actually
C. chlorophaea.]
So yes, I think you have true
C. pyxidata.
4. Assuming the basal squamules we see go with the podetia, then this is not
C. chlorophaea, though
Cladonia species often grow intermixed (and, frighteningly, at least one species is known to be able to grow into the thalli of other
Cladonia spp. to produce a single, mixed thallus!).
Anyhow, as far as I can tell from the photograph, I suggest this is
C. humilis, which is frequent on sea-cliffs.
5. I don't think this is a lichen. Almost certainly it is the green (!) alga,
Trentepohlia, with the bright colour and cushion-like growth suggesting
T. aurea.
6. & 7. Yes, undoubtedly the two
Roccella species.
8. Yes,
C. portentosa. (There is a closely related, extremely rare and critically endangered species on the serpentine in W. Cornwall but, sadly, your photograph shows the trichotomously branched tips of the common species.)
9. No doubt about this one either. Until such unlikely time as someone find the very northern
Letharia vulpina somewhere in the Scottish Highlands,
T. flavicans is unmistakable in the British lichen flora.
A nice set, Tiggrx.
A booklet more people ought to know about is '
Lundy Lichens' by Anne Allen. Only 48 pages, but full of photographs and a good introduction to coastal lichens of the South West. Details on how to obtain it are on the British Lichen Society's website:
The British Lichen Society
Alan
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