Unknown on rotten log

[RobSutton]

Found on a well rotten, debarked log of either ash, beech or sycamore (all grow adjacent).



Microscopically couldn't get much from it (it seems well past it's best), apart from these which I'm not even sure are fungal but looked most spore like from amongst all the mass of algal cells which seem to have colonised it.



Any thoughts, ideas, suggestions welcomed as usual.

[Chris Yeates]

hi Rob (and a belated thanks for the report!)

it looks rather like Berlesiella nigerrima, which occurs on old stromata of Diatrype, Eutypa and other such pyreno's, though I have never seen it covering so much surface area, and would therefore err on the side of caution

I think those are stray conidia of another, unrelated fungus . . .

best I can do

Chris

[RobSutton]

Hi Chris

I had another go at the microscopy and found these in situ in a sample taken from one of the perithecia. From the size, shape and colour of the spores could they be from a Eutypa sp?



Reading up on your suggestion of Berlesiella nigerrima could the photo actually show both species? The small round pock-marked bits being the Berlesiella on and amongst the smoother Eutypa? Cutting a section through the specimen there was a greenish yellow colour in places that I took to be algae (and there were certainly plenty of algal cells in the prep.) but I read that Eutypa flavovirens has such a coloured stromata so could it be this species? Too many questions - I think I need to go back and try and find another specimen I can section and photograph to demonstrate these observations.

[Chris Yeates]

definitely on the right lines I suspect Rob!; if the diatrypaceous fungus is producing spores you might get lucky with the Berlesiella as well (though that may be immature of course)

cheers

Chris