Search found 47 matches

by Mark Powell
Mon May 04, 2020 3:42 pm
Forum: Lichens
Topic: Hoping for a hand...
Replies: 8
Views: 293

Re: Hoping for a hand...

For some reason the image didn't attach. Here is Haematomma ochroleucum.
by Mark Powell
Mon May 04, 2020 3:41 pm
Forum: Lichens
Topic: Hoping for a hand...
Replies: 8
Views: 293

Re: Hoping for a hand...

Your fourth image shows a leprose lichen, consisting entirely of (slightly fluffy) minute granules. It is a toss-up between Lepraria lobificans and L. vouauxii . I will attach an image of Haematomma ochroleucum which has a distinct fimbriate margin (like combed cotton wool). The central parts of H. ...
by Mark Powell
Mon May 04, 2020 3:35 pm
Forum: Lichens
Topic: Hoping for a hand...
Replies: 8
Views: 293

Re: Hoping for a hand...

I can't make anything much out from your third image so I won't try to identify it. I will attach an image of Candelariella medians. Note that it is crustose-placodioid again. It has a paler lemony colour compared with Caloplaca flavescens and a simple chemical test distinguishes the two genera.
by Mark Powell
Mon May 04, 2020 3:31 pm
Forum: Lichens
Topic: Hoping for a hand...
Replies: 8
Views: 293

Re: Hoping for a hand...

Your second image again shows a crustose-placodioid lichen which rules out Xanthoria parietina (which is foliose). Note how closely appressed the lobes of your lichen are and if you tried to pull the lobes off the surface you would find that they are attached. Your lichen looks like Calopaca flavesc...
by Mark Powell
Mon May 04, 2020 3:26 pm
Forum: Lichens
Topic: Hoping for a hand...
Replies: 8
Views: 293

Re: Hoping for a hand...

In fact my first image showed two similar grey placodioid lichens. In lower centre is a rounded thallus of Caloplaca teicholyta , this is flanked to right and upper left by two thalli of Aspicilia radiosa . The latter has somewhat larger lobes, is a rarer lichen of old limestone and yours will almos...
by Mark Powell
Mon May 04, 2020 3:21 pm
Forum: Lichens
Topic: Hoping for a hand...
Replies: 8
Views: 293

Re: Hoping for a hand...

I agree with the above from Glos lichens, that your lichen lacks fruiting bodies and appears too lobate for Lecanora campestris . I feel fairly certain that your first image shows Caloplaca teicholyta - at least that is the one that I would investigate further. C. teicholyta is rarely fertile, when ...
by Mark Powell
Sun Apr 12, 2020 2:59 pm
Forum: Lichens
Topic: Hypotrachyna afrorevoluta or revoluta ?
Replies: 3
Views: 328

Re: Hypotrachyna afrorevoluta or revoluta ?

My feeling is that you are right with the genus Hypotrachyna and that you are trying to decide between the right pair of species. I am not quite sure I would go as far as saying that you should have ignored it, but it is true that the separation of this pair is best done with well-developed, 'typica...
by Mark Powell
Thu Mar 19, 2020 11:10 am
Forum: Lichens
Topic: Odd Micarea from my First Social Distancing Lichen Trip
Replies: 5
Views: 693

Re: Odd Micarea from my First Social Distancing Lichen Trip

I remember Brian describing Fellhaneropsis vezdae as a species that has 'gone out of fashion'. I suspect that your suggestion of a decline due to de-acidification is highly likely. Sterile F. vezdae was one of the first 'mysteries' that I came across in my early days (2008). Then I found fertile tha...
by Mark Powell
Thu Mar 19, 2020 9:28 am
Forum: Lichens
Topic: K/UV reaction
Replies: 9
Views: 807

Re: K/UV reaction

The K/UV+ yellow will almost certainly be useful in helping to separate Lecanora alboflavida from some of its near look-alikes such as e.g. Pertusaria flavida (which is probably K/UV- when someone gets around to checking). However, I would urge you to use these new tests with caution and to use know...
by Mark Powell
Thu Mar 19, 2020 9:09 am
Forum: Lichens
Topic: Odd Micarea from my First Social Distancing Lichen Trip
Replies: 5
Views: 693

Re: Odd Micarea from my First Social Distancing Lichen Trip

Hi Neil,
Have you considered Fellhaneropsis vezdae? That is just a suggestion off the top of my head at the moment but it might be one to check; most of the characters seem to fit fairly well.
Mark
by Mark Powell
Wed Mar 18, 2020 5:11 pm
Forum: Lichens
Topic: Physconia grisea and P enteroxantha
Replies: 1
Views: 476

Re: Physconia grisea and P enteroxantha

Sorry to be lazy and answer this with a link: https://twitter.com/obfuscans3/status/1217429868499099649 As you will see, in my opinion LGBI2 is rather misleading about the rhizines of P. grisea. They can be considerably darker and also quite considerably 'frayed' (even branched) than is stated and i...
by Mark Powell
Mon Mar 16, 2020 10:10 pm
Forum: Lichens
Topic: K/UV reaction
Replies: 9
Views: 807

Re: K/UV reaction

I have just dug out my scans which I can attach here (you may still like to go and browse my twitter 8-) ). The first (and so far only) formal publication of K/UV reactions was: Powell, M. (2018) Spot tests and staining: some recent advances. Bull. Brit. Lichen Soc. 123: 77-82. [The Winter 2018 edit...