Never Take Fungi For Granted . . .

[Chris Yeates]

. . . or at least never think that that species you have been recording for ages has been correctly named by you

I recently posted about the dangers of assuming that the small bright red Nectrias on old pyrenomycetes might not all be N. episphaeria (or N. magnusiana on Diatrypella)

http://www.wildaboutbritain.co.uk/fo...7-post132.html

one often sees these on the flat grey to black stromata of Diatrype stigma: John posted something about this a while back:

Originally Posted by FungiJohn

It just struck me that we didn't have a single image of Diatrype stigma in the Gallery, let alone Nectria episphaeria



John

the trouble is that what we have happily been calling Diatrype stigma is a member of a species complex of three or four separate species. I have been vaguely aware of this for a while but what brought it into sharp focus was this post on ASCOFrance:

Sordariomycetes - Xylariales (note the comment at the bottom about "non-initiates"); I therefore posted on the same site requesting clarification - Diatrype decorticata - Forum ASCOFrance - you will see I quickly received a helpful reply with a link to the paper which does indeed seek to clarify the situation; sadly for many WABbers you'll see it's in French, but I shall translate the key bits for anyone who's interested when I get the time

from a preliminary peruse it would appear that the best character for telling them apart is the size of the conidia produced in culture - so not too helpful for most people there; however he does point out distinguishing features of the fungi as seen in the field (followed by microscopy, of course!); plus - rather as is the case with the species-complex around Daldinia - there do seem to be host relationships; for example as I read it Diatrype stigma does not occur on Fagus - the likelihood is that you will have D. decorticata there (so there go 650 records on the FRDBI database)

more on this anon; also while you are on the ASCOFrance site note this:
incertae sedis - incertae sedis

which is the name we should now be using for rhododendron bud-blast

cheers

Chris

[fairplay]

Hi Chris,

What I have been calling a Diatrype stigma look-a-like on Corylus for yonks, is that still most likely to be D.stigma ?

Also, I am confused with the bud blast new name - you seem to be saying 'incertae sedis' is the new name, but with no capital letter for the 'i' and trying to translate it, I can only assume that incertae sedis means 'insert this' and that we have to look inside for the new name which would appear to be:
Seifertia azaleae, but then I look underneath and note Class, sub Class and Order all have incertae sedis next to them as well.

It all looks French to me !

Neil.

[Chris Yeates]

Originally Posted by fairplay

Hi Chris . . . . you seem to be saying 'incertae sedis' is the new name, but with no capital letter for the 'i' and trying to translate it, I can only assume that incertae sedis means 'insert this' . . . . .

Neil.

I don't know Neil . . . .

only days ago I explained (in answer to a direct question from your good self what "incertae sedis" means: Black asco on pallet)

when you hyperlink to another website, that hyperlink (which in WAB is blue) is given a name - sometimes obvious and sometimes, as in the case above less so; ASCOFrance clearly labels its posts taxonomically from top down - as the taxonomic position of rhododendron bud-blast is uncertain you get the two "incertae sedis" levels; but whatever the link is called it takes you straight to the page where all is (or should be) made clear . . . . it cannot be called Pycnostysanus azaleae as the type species of Pycnostysanus is P. resinae and that fungus differs structurally, in its DNA and in its lifestyle (on pine resin, not as a virulent plant pathogen) from azaleae that a new genus Seifertia had to be erected for it

Originally Posted by fairplay

. . . . .
It all looks French to me !

Neil.

errrrmmm it's a French website, or rather based in France; contributors are world-wide however (most in Europe of course), they include regular contributions from Zotto Baral and Stip Helleman on inoperculates and several very good French workers on nectriaceous fungi - it's a very useful site imho; you will note however that there is a Union Flag at the top which you can click for an English version; when I am conversing with someone who has not claimed to have English as a language, out of courtesy I have written in my best attempts at French (and included where deemed necessary) an English translation

Originally Posted by fairplay

Hi Chris,

What I have been calling a Diatrype stigma look-a-like on Corylus for yonks, is that still most likely to be D.stigma ?
Neil.

there have been later posts on the thread if you look, and both Alain Gardiennet and Jacques Fournier say that in their experience D. stigma and D. decorticata are common on Corylus; in answer to a question I posed Alain is doubtful about the reliability of host as an identification aide, Jacques reaffirms that Rappaz's original studies of the diagnostic conidial stages they are limited to decorticata on Fagus and stigma on Quercus; important macroscopic characters are the colour of the stroma (subtly different) and the manner of cracking of the mature stroma

I think it would be a good exercise for WABbers to collect and photograph "Diatrype stigma" collections on a range of hosts, noting the colour (whether greyish-black or brownish-black - see: Sordariomycetes - Xylariales again for the latter) and pattern of cracking - a useful winter exercise methinks . . . . (one must also of course be certain that one is not actually looking a Eutypa )

phew!

Chris

[Chris Yeates]

looking at John's photo: Diatrype stigma - Wildlife Photography I wonder whether this could not be on Betula . . . in that case, and with those very prominent ostioles, this could be Diatrype undulata = Calospora undulata

cheers

Chris