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07-02-2023 22:28

Ethan Crenson

Hello friends, On Sunday, in the southern part of

19-02-2026 17:49

Salvador Emilio Jose

Hola buenas tardes!! Necesito ayuda para la ident

09-02-2026 22:01

ruiz Jose

Hola, me paso esta colección en madera de pino, t

19-02-2026 13:50

Margot en Geert Vullings

We found this collection on deciduous wood on 7-2-

19-02-2026 12:01

Castillo Joseba Castillo Joseba

Me mandan el material de Galicia (España), recole

17-02-2026 09:41

Maren Kamke Maren Kamke

Good morning, I found a Diaporthe species on Samb

16-02-2026 21:25

Andreas Millinger Andreas Millinger

Good evening,failed to find an idea for this fungu

08-12-2025 17:37

Lothar Krieglsteiner Lothar Krieglsteiner

20.6.25, on branch of Abies infected and thickened

17-02-2026 17:26

Nicolas Suberbielle Nicolas Suberbielle

Bonjour à tous, Je recherche cette publication :

03-02-2013 19:50

Nina Filippova

Good time), I've compared this specimen with the

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Pirottaea sp. ?
Chris Yeates, 03-03-2012 18:06
Chris YeatesHello everyone

here is a discomycete found on dead fallen stem of Chamerion angustifolium; it developed after being kept damp for several days.
Apothecia erumpent, globose becoming discoid, blackish with blackish or slightly paler discs; ectal excipulum with dark cells - 1-2 celled below becoming multicellular toward the disc margin with blunt apices.
Asci 25-30 x 4.5-5µm; (surprisingly) none showing any blueing in Lugol - pre-treatment with KOH not yet attempted.
Ascospores 8-9.5 x 2 µm, with no, or only only small, guttules at each end, rounded above, slightly tapered below.
This seems to me to be a good Pirottaea (if one accepts the genus as distinct); of the 11 species of Pirottaea recorded for Britain so far this does not seem to match any of them; in addition as I understand it this is a largely host-limited fungal genus, and no species have been recorded on Chamerion (or Epilobium) in the UK.

I would welcome any comments


amitiés


Chris

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Hans-Otto Baral, 03-03-2012 18:14
Hans-Otto Baral
Re : Pirottaea sp. ?
Hi Chris

first, I must doubt the inamyloidity of the asci. Because I see you have nice living asci of a Helicogonium with biguttulate clavate spores on your pics. Quite large oildrops, unlike the free spores which are narrower, more cylindrical.

So Helicogonium, probably trabinelloides, typically of Pyrenopeziza s.l., named after the spores resembling "Phaeohelotium" trabinellum. All Helicogonium are inamyloid.

The hairs of the Pirottaea: are they laterally thickwalled and darker? It seems a bit, so perhaps P. imbricata

Zotto
Chris Yeates, 03-03-2012 21:25
Chris Yeates
Re : Pirottaea sp. ?
hello Zotto

I was struck at the time by how a number of the asci seemed "wrong" for a mollisiaceous discomycete and of course these were the ones which became easiest to examine in a squash - for one thing they had distinct apical "caps" and of course they were I- which was not what I was expecting; so most of my comments re the asci (above) clearly refer to the Helicogonium. This is a genus which I have not (knowingly) come across before - I shall be a little wiser in future! Having worked through your key I am sure this is indeed H. trabellinoides, based on spore number and size, "cap" shape, presence of croziers and host.


I have now had chance to consult Nannfeldt's review of Pirottaea in Symb.Bot.Upsal. XXV:1, and also your drawings and photographs on the DVD. I think Pirottaea cf. imbricata is indeed the best place to file this. Do you think that under this name lies a species-complex of morphologically near-identical taxa on a wide range of hosts??


many thanks as ever for your help


Chris

Hans-Otto Baral, 03-03-2012 22:27
Hans-Otto Baral
Re : Pirottaea sp. ?
yes, I think Pir. imbricata needs more detailed study, maybe there are several similar species. But I have seen only a few records, and I noted that Nannfeldt's work is not as detailed as needed, though we can be lucky to have it. The hair character of laterall wall thickening is not obvious in his pics, as far as I remember.

Zotto