Stumped, or sleepered
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May 30, 2019 at 1:08 pm #31292
Found on the vertical face of a railway sleeper being used as a gate post. Thallus C+ yellow, K-
Apothecia black, Lecideine.
Upper hymenium green, unchanging in KOH.
Spores in water simple: 11.5-15.3 x 4.6-5.4 µm.
Spores in KOH-ink-vinegar with septum: 13.9-15.5 x 4.1-5.2 µm.
Paraphases in KOH-ink-vinegar filiform, anastomosing.
Any help welcome.
May 30, 2019 at 8:20 pm #42039Chris The yellowish thallus and black apothecia looks like
Buellia ocellata, the C + reaction (but ideally should be orange rather than yellow), the colour of the apothecia cross section matches and your stained spores are clearly one septate (when you looked at the spores in water they looked simple, but most spores need clearing in at least K to be sure what is going on inside, and nitric acid or staining may be necessary in some difficult spores). The spores look under developed and pale for Buellia ocellata, but I am fairly sure that is what this it. Old hard and treated timber can support some normally saxicolous species, which leads to confusion in keys that use the normal habitat of lichens as early splits. Buellia ocellatahas occasionally been found on worked timber see http://www.dorsetnature.co.uk/pages-lichen/lch-233.html ” class=”bbcode_url”> http://www.dorsetnature.co.uk/pages-lichen/lch-233.html Neil
May 31, 2019 at 2:30 am #42040Neil: I’m not convinced. The spores are the wrong shape (too narrow) for B. ocellata – not to mention not pigmented – and B. ocellata has a dark hypothecium and a much reduced exciple. I don’t have a better suggestion, mind.
Alan
May 31, 2019 at 7:26 am #42041Neil Thank you for taking the trouble to reply. It’s an interesting thought but I have to agree with Alan that the spores especially don’t fit even closely. These were hyaline in water and much too narrow. I did another C test and it remained yellow.
Chris
May 31, 2019 at 1:11 pm #42042Chris Yes on I am wrong on the
Buellia ocellata, suggestion. The C + yellow reaction should narrow things down, these are not common. However, I can not think what it is but does not match any typically lignicolous species I know, so I suspected it may be a mainly saxicolous species; I know these less well. Neil
June 27, 2019 at 1:18 pm #42043An update on this one. Subsequently, I found picnidia with tadpole-like conidia, clearly not Lecanoran. Brian Coppins kindly agreed to look at it and here are his comments: Many thanks for the ‘sleeper’ specimen. The lichen is Lecanora symmicta, at least in a broad sense. We may well have 2 or 3 taxa covered by this name. Species of this complex occasionally have some spores that are 1-septate, or more rarely 3-septate.The epithecium has tiny granules that disappear in K. The exciple is composed of radiating branched hyphae that are sublax in K, and the asci are Lecanora-type. The tadpole-shaped conidia are not of the lichen, but the lichenicolous Diplolaeviopsis symmictae – see attached. I couldn’t find any apothecia of the Diplolaeviopsis, which contrast with my collection from East Lothian, which has apothecia but no pycnidia.I’ll curate your specimen for E, and prepare a NRI entry for the BLS Bulletin.
A request has been received for fresh material for sequencing – in hand.
Many thanks to Brian.
Chris
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