Possible Roccella?

[JennyS]

I came across this one on a coastal rock today and wondered if it could be Roccella phycopsis?
Confirmation or correction would be very appreciated - there don't seem many Irish records in Dobson and LichenIreland hasn't a distribution map for it so I'm wondering if its just a battered-looking something-else....

[JennyS]

I've just got Frank Dobson's 'Lichen-Identifier' CD (multi-access key) and from that Ramalina chondrina looks to be a maybe-possibility ......?

[poschiavanus]

I'd never heard of Roccella before your post: so I'm afraid you're out on your own on this one!

[AlanS]

Hi Jenny,

I have never seen either Roccella (hoping to rectify that quite soon) but my understanding of R. phycopsis is that the branches are pretty solid in cross-section, with maybe just a narrow diameter cental hole, whereas your photograph shows something with very hollow branches. The 'ulcerated' look of the surface some of the branches is very Ramalina-like.

One rare possibility, not out of the question in your area, is Ramalina portuensis, which apparently has branches tending to be round in cross-section rather than flattened (never seen it either). I don't believe it is R. chondrina - too coarse and branching looks wrong.

However, can we completely rule out the multi-variable, ever-annoying mistress* of disguise that is R. siliquosa? A check in 'Purvis' confirms that it has forms with branches that are more or less rounded. One or two of the branches in your photograph are flattened and rather curved, like a scythe, which I find a useful character for spotting R. siliquosa amongst R. cuspidata.

*The Latin name is female gender.

I don't know, but I think R. siliquosa is a possibility, allbeit very different from how it usually looks.

But don't give up on looking for Roccella species though - they must be possible in your area.

Alan

[JennyS]

Thank you Alan - yes, after going back to that one it does seem to check out as a very snail-munched and battered R. siliquosa, but I'll keep hoping to come across Roccella at some point!