Search found 40 matches

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: 533

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: 573

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: 533

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: 364

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: 573

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...
by Mark Powell
Mon Mar 16, 2020 9:56 pm
Forum: Lichens
Topic: K/UV reaction
Replies: 9
Views: 573

Re: K/UV reaction

When you click on my twitter link (previous post), you will need to scroll down the thread to see the scans of the Bulletin article detailing the K/UV reactions.
by Mark Powell
Mon Mar 16, 2020 9:54 pm
Forum: Lichens
Topic: K/UV reaction
Replies: 9
Views: 573

Re: K/UV reaction

I wrote a fair summary in the Bulletin and scans of this have been posted on my twitter: https://twitter.com/obfuscans3/status/1207602169828069376 If you need further information, then do let me know. So far, it is still the atranorin and confluentic acid tests that have proved potentially useful (t...
by Mark Powell
Tue Feb 11, 2020 10:52 am
Forum: Lichens
Topic: A problematic Parmelia
Replies: 13
Views: 777

Re: A problematic Parmelia

I wholeheartedly agree with the tone of Chris and Neil's replies. If anyone has any genuine queries then we can all learn from having them posted on this forum. There are two aspects in particular that I like about airing queries in public. First is the way that so many others can learn from the dis...
by Mark Powell
Mon Feb 10, 2020 5:58 pm
Forum: Lichens
Topic: A problematic Parmelia
Replies: 13
Views: 777

Re: A problematic Parmelia

It could be a chemical var. without usnic acid but perhaps more likely to be an individual in which the usnic acid colour is less apparent. Perhaps specimens growing in shade (or other environmental factors) leads to them having lower concentration of usnic acid. I have a nice specimen of X. tinctin...
by Mark Powell
Mon Feb 10, 2020 5:02 pm
Forum: Lichens
Topic: A problematic Parmelia
Replies: 13
Views: 777

Re: A problematic Parmelia

I am going to throw another suggestion into the mix, not a definite identification at this stage. What about Xanthoparmelia conspersa ? Although I would expect X. conspersa to be a yellow-green colour, that does depend on the specimen and the lighting. Mark, when viewed in daylight, does the thallus...
by Mark Powell
Mon Jan 13, 2020 1:22 pm
Forum: Lichens
Topic: Hairy Jelly
Replies: 7
Views: 567

Re: Hairy Jelly

I tried to key out Juliet's lichen with the new Collemataceae key, assuming that we have decided that it doesn't have any true 'tomentum' and arrived at couplet 40 where we are asked whether it is a) On calcareous soil, brick or mortar b) On rocks or amongst mosses on rocks Scytinium turgidum and S....
by Mark Powell
Mon Jan 13, 2020 12:48 pm
Forum: Lichens
Topic: Hairy Jelly
Replies: 7
Views: 567

Re: Hairy Jelly

The draft definition of tomentum for LGBI3 has been slightly expanded and is currently as follows: tomentum (-ose), felt-like mat of hyphae; a special case of pubescence in which the soft hairs are matted and usually pressed close to the surface. For reference: pubescent , having soft, short hairs (...