Graphis scripta ?

[Lindsay-c]

Is this Graphis scripta ... the diameter of these varied but this one was approximately 3cm - not sure what the tree was it was on and there were numerous patches of this all the way up the trunk...

[basquesteve]

I think its a mold,fungi belonging to the family Schizoporaceae but its not my subject

[Lindsay-c]

Thanks I shall post it in the elsewhere and see if any fungi fanatics recognise it...

[Chris Yeates]

hi

definitely not Graphis scripta - I'm wondering whether it could be a member of the Atheliales, a group of basidiomycete fungi some of which parasitise lichens on trees and have this sort of growth form . . .

Chris

[Rich1990]

I am often wrong but this to my untrained eye looks like it could be Cryptothecia striata? The picture looks very similar to the picture of this species in Lichens of North America.

R.J

[AlanS]

Originally Posted by Rich1990

I am often wrong but this to my untrained eye looks like it could be Cryptothecia striata? The picture looks very similar to the picture of this species in Lichens of North America.

R.J

Hi Rich.

Lichens of North America is a superb book, as you have just discovered, but of course it has many genera and species of lichen that we don't have in Britain. On the other hand, some we don't think we have may turn up.

Unfortunately, the map in that book shows that Cryptothecia striata, even in North America, is restricted to Florida. The genus Cryptothecia in fact does seem to be entirely tropical and subtropical. Its distinctive feature is that the spores are not released from organised fruit-bodies on the thallus, and without being able to confirm that feature, it appears that distinguishing it from immature crusts of other species is difficult. Apparently the thallus is typically quite thin, with some species being foliicolous, i.e. growing on the surfaces of tough leaves of tropical trees. I cannot say that the suggestion is wrong, but it has to be very, very unlikely.

As to what Lindsay-c's fungus/lichen is ... ???

I have avoided making any suggestion so far. We are all agreed it is not Graphis scripta, which is a smooth, pale to white lichen with fruit-bodies that resemble writing (more like Hebrew than any western script). [I wonder if any Hebrew scholars have ever examined it? Maybe the answers to Life, the Universe, and Everything are written on our trees? Or maybe not.]

Is it a lichen or a non-lichenised fungus? Folks have argued both ways and I really don't know. Chris Yeates's suggestion of a non-lichenised fungus in the Atheliales makes a lot of sense. At the top-left we see a smaller, younger thallus, with a thin, cottony margin, that looks a lot like an Athelia, but the green colour is unlikely. A. arachnoidea is a common species with the reputation of being a lichen parasite, which indeed it is, but basically it is a species that attacks and kills coccoid green algae, whether they are free-living or within a lichen. I am fairly sure our mystery is not that, but could it be another Athelia species or someting related? An admittedly quick check of relevant literature doesn't seem to turn up anything, and the green colour is a difficulty.

As Rich has had the courage to throw in a speculative suggestion, I'll do the same. My very first thought when Lindsay-c posted this was that it could be very immature Pertusaria pertusa. I looked at some photographs I have of young colonies and decided it wasn't - but P. pertusa does start out life as circular, well-defined, greenish colonies with a conspicuous white margin (prothallus). These seem to be too green, but I wonder? I found it forming abundant circular colonies up the trunks of some coppiced Sycamore and thought I had something new and exciting, and when I found a more mature thallus was starting to produce the familiar "pepper-pot" apothecia it was quite a shock. This is a very tentative suggestion, and almost certainly wrong, but I am throwing it into the discussion as my best (but pathetic) shot.

Alan
(Going to bed now - it is late and I am very tired. When I wake up tomorrow I'll consider my Pertusaria suggestion even sillier than I think it is just now.)

[Fauna]

I believe this is the same as Lindsay-c?



I've no idea what it is, it was found growing about 100yds from my house so i have a perfect opportunity to keep an eye on it. It did stand out amoung the bunch, it was really "bright" you could spot it a mile off.

[AlanS]

Originally Posted by AlanS

As Rich has had the courage to throw in a speculative suggestion, I'll do the same. My very first thought when Lindsay-c posted this was that it could be very immature Pertusaria pertusa. I looked at some photographs I have of young colonies and decided it wasn't - but P. pertusa does start out life as circular, well-defined, greenish colonies with a conspicuous white margin (prothallus). These seem to be too green, but I wonder? I found it forming abundant circular colonies up the trunks of some coppiced Sycamore and thought I had something new and exciting, and when I found a more mature thallus was starting to produce the familiar "pepper-pot" apothecia it was quite a shock. This is a very tentative suggestion, and almost certainly wrong, but I am throwing it into the discussion as my best (but pathetic) shot.

Alan
(Going to bed now - it is late and I am very tired. When I wake up tomorrow I'll consider my Pertusaria suggestion even sillier than I think it is just now.)

Yeah, I got up the next day, and did rather regret posting the above, but ...

At last I have had the chance to go and look at the coppiced sycamore I mentioned. Sunday was rather dank - some lichens were just too wet, but others were in good, fresh condition. The immature Pertusaria pertusa colonies were really very green in the damp atmosphere, with nice white margins. It was very conspicuous, with the neat circular colonies going up the trunks, and I saw more of the same on other trees.

Now I am not going to be definite on species - immature colonies of certain other Pertusaria species might well be very similar, but I no longer think my suggestion was silly.

I feel pretty confident that the photo posted by Fauna is an immature Pertusaria (quite possibly P. pertusa), and with reasonable confidence I say the same for the original photo by Lindsay-c that started this thread.

Unless anyone produces a counter argument, I now believe we have this nailed!

Alan