synan's picture

Baeomyces placophyllus

Observed: 2nd July 2012 By: synansynan is knowledgeable about Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichenssynan’s earned reputation in Fungi and Lichens
Baeomyces placophyllus
Baeomyces placophyllus (4)
Baeomyces placophyllus Stereo
Baeomyces placophyllus Stereo (2)
Baeomyces placophyllus Stereo (3)
Baeomyces placophyllus Stereo (4)
Baeomyces placophyllus Stereo (5)
Baeomyces placophyllus Stereo (6)

Green, squamulose thalli on spoil heap at disused lead mine, densely covered in pale, discoid schizidia. Black ascomata seemingly epiphytic/parasitic on the thallus in the background of pic 1 (I have a sample I will attempt!?! to ID at some point). Pic 2 shows apothecia developing, which are reportedly rare.
Edit: 6 new images appended. These might later be moved to a new observation.


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Species interactions

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AlanS's picture


I found this myself for the first time a week ago.

My take on the apothecia is that immature apothecia may be quite common, but fully developed apothecia (as illustrated in Holien & Tønsberg, Norsk lavflora, pg. 192) are rare.

Someone is going to be interested in the fungus, I feel sure. I may trawl through such information as I have on lichenicolous fungi to see what possibilities might be.


AlanS's picture

The parasite

There may be other possibilities, but two to check, known on this host, are:

Cercidospora parva: pyrenocarpous fungus, with perithecia embedded in the host, asci with 4-8 spores, ascospores 1-septate, said to be 12-15(-16) x 4-5(-6) µm.

Arthrorhaphis grisea: a lichenicolous lichen, so is described in Lichens of Great Britain and Ireland, has sessile apothecia on the lobe surfaces (not embedded so so not matching your material), very long (to 50 µm or more), narrow, multi-septate ascospores, but also has immersed pycnidia, which might be what you have there. Presumably they produce simple conidia, no description to hand (very small and tear-drop shaped in a related species).

Both produce greyish areas on the host, so it depends on what those black fruiting bodies are. Seems to me that a quick squash should produce spores that are going to be instantly diagnostic.

If you work this out, I would be interested to know.
Information on Cercidospora parva from draft (unpublished) keys by Hawksworth, Atienza & Coppins (not to be formally cited).


synan's picture

A big thank you...

... for the info. I'll try to look at it this week, and will let you know how I get on.


synan's picture

A first look

I didn't notice the parasite in the field, and it was only while examining it under a dissecting microscope that I spotted the black ascomata and then found them in the photo. Unfortunately, therefore, I have just discovered that my sample misses most of the action on the thallus itself. I have plenty of fruit bodies that aren't in contact with the lichen (eg the left part of the 'infected' area in the original photo), but only one body immersed in the thallus (5th photo).

Anyway, working with what there is: a quick squash of one of the non-immersed fruits yields colourless, fusiform spores, 3-5 septate and 18-28 x 5μm. I struggled to recognise how many were in the asci, but it's in the region of 4-8. I think the paraphyses are simple and not anastomosing, but I should revisit them and the ascus tips with oil immersion when I find the time, and look at the immersed ascocarp.

The fruit bodies appear perithecia-like (they seem to have an ostiole) and to be associated with a granular/squamulose thallus, so perhaps we have a lichen. I am wondering if the immersed body is identical to the others, but competing to break through the Baeomyces thallus. I recall Andre Aptroot's comment in the Bulletin, about Xanthoria parietina being overgrown by Pertusaria albescens. Just a thought - probably completely wrong.


AlanS's picture

Unfortunately ...

these additional photographs are not the same thing.

I had intended to mention that you had a scrap of a Micarea, most likely M. lignaria, in the first photo.

All six of your additional photographs also look like Micarea (lignaria or similar taxa).


synan's picture

Argh! Unlucky

Oh well. I was pleased to find B. placophyllus, and the other species are an added bonus, but 3 in 1 would have been good. Maybe if it hadn't been so wet I would have got down to have a closer look.

Thanks for Micarea - I will follow up on that and might move the photos to a new observation.

And I'll add this mining site to the growing list of places I want to revisit.