Three from rocks

JennyS · #1 (**permalink**) 13-05-2009, 12:38 AM

The three below were all on rocks and confirmation / correction would be much appreciated!

1. On top of acidic rock at side of stream, probably submerged when water-levels high - Dermatocarpon leptophyllodes below D. luridum?

2. On acidic upland rock - Fuscidea cyathoides plus something parasiting it?

3. On limestone, Aspicilia species? Weird placioid form of A. calcarea or might it possibly be something interesting like A. radiosa (she says hopefully!)

AlanS · #2 (**permalink**) 16-05-2009, 12:58 AM

1. I don't know Dermatocarpon, have never seen one. When I find one, I may well post it here for your confirmation, Jenny.

2. Hmmmm. There do seem to be two kinds of apothecia, strongly suggesting a parasite, but the small apothecia that seem to own the crust don't really look like Fuscidea to me.
On the other hand, I have just checked your photograph againsts a lump of rock that is lying around in my kitchen that I think does have Fuscidea on it, and I could believe it is the same thing. The bean shaped spores should be a clincher.

3. Oh, how nice! I have never seen A. radiosa, but I cannot believe it is anything else. Certainly not A. calcarea.

Alan

JennyS · #3 (**permalink**) 16-05-2009, 01:16 AM

Thanks Alan - if that is A. radiosa it was a good find!
Let me know if you'd like samples of Dermatocarpon to have a look at as I can easily send you some ....

JennyS · #4 (**permalink**) 16-05-2009, 09:56 PM

Slight re-think on the possible A. radiosa - could it be Solenopsora candicans instead with that black prothallus?

AlanS · #5 (**permalink**) 17-05-2009, 08:50 PM

Quote:

Originally Posted by JennyS

Slight re-think on the possible A. radiosa - could it be Solenopsora candicans instead with that black prothallus?

I don't think the black prothallus is diagnostic. As I said, I have never seen Aspicilia radiosa, but your photograph seems to match other pictures with those narrow marginal lobes and black (not pruinose) apothecia.

On the other hand, I have seen quite a lot of Solenopsora candicans very recently and I would say that your photograph does NOT match it.

I think your original diagnosis is correct. Evidently it is a good record in Ireland, but since it is widespread on the English and Welsh limestone, it seems reasonable that you should have it too.

By the way, I saw an American book last week with several photographs of fruticose Aspicilia species looking not unlike Cladonia furcata. (Contemplates, yet again, giving up on lichens.)

Alan

JennyS · #6 (**permalink**) 18-05-2009, 02:19 AM

Hi Alan, and thanks for the reassurance on my initial A. radiosa ID.
I think I'll have to make an excuse for a 200 mile drive to try and refind it and collect a specimen ......

When you say that the black prothallus isn't diagnostic does that mean that its just a variable feature that might or might not be present?

(And if I ever have the misfortune to come across an aspicilia that looks like a cladonia I'll definitely have to quit! My remnants of pre-lichen sanity can only take so much ........)