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22-07-2010 23:59

Martin Bemmann Martin Bemmann

Dear all, since some days I enjoy scanning a pi

21-07-2010 13:41

Marja Pennanen

Hello, I've overcollected ascomycetes now after i

20-07-2010 16:26

Marja Pennanen

Hello, I found these on some Carex leaves. They a

20-07-2010 14:30

Enrique Rubio Enrique Rubio

Hi to all: I need your help about this small (up

19-07-2010 15:50

Gernot Friebes

Hi again, here I have the second collection and

19-07-2010 15:39

Gernot Friebes

Hi, Leptosphaeria is a really complicated genus

17-07-2010 11:20

Marcel LECOMTE

Bonjour les amis, En coupant ma haie, j'ai trouv

16-07-2010 09:38

Marja Pennanen

Hello folks, these clumbs are about 0,5 to 1mm w

16-07-2010 00:45

Martin Bemmann Martin Bemmann

Hi again, I found these today on a dead stem of

15-07-2010 23:07

Miguel Ãngel Ribes Miguel Ángel Ribes

Good night I have this small Lachnum (2-3 mm di

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Leptosphaeria ??? on Quercus
Martin Bemmann, 22-07-2010 23:59
Martin BemmannDear all,

since some days I enjoy scanning a piece of oak wood I collected behind the house I'm living.
So far it featured Orbilia aprilis, Mollisia ligni and Rhamphoria pyriformis.
This evening I checked for further species and I found an even mor tiny one than the Rhamphoria (there are still more tiny ones, I'm afraid...).

The perithecia have the shape of a lentil, the lower part immersed in the substratum, brown speckled, partially hyaline. Size (on the slide with cover glass) is 350 µm in dm. of the largest specimen I found.
The ostiole (again on the slide) measured 50 µm in dm. (quite large I think).
The asci are cylindric with a short stipe and measure 54,5-74,9 x 11,8-13,8 µm.
Paraphyses are multi-septated and sometimes branched (c. 3 µm thick)
Now the spores ( those made me think on Leptosphaeria by shape): they are hyaline and clavate with 3 septa and tapered at the septa. Size is (16,4) 17,7 - 21,9 (22,3) x (5,5) 6,3 - 7,6 (7,9) µm

Any idea is very appreciated!

Best regards,

Martin






  • message #12420
Martin Bemmann, 22-07-2010 23:59
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
here an overview:
(there is a dead nematode below and the brown dots are stray spores of another fungus)
  • message #12421
Martin Bemmann, 23-07-2010 00:01
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
here are some asci:

  • message #12422
Martin Bemmann, 23-07-2010 00:01
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
paraphyses:

  • message #12423
Martin Bemmann, 23-07-2010 00:02
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
and the spores:

  • message #12424
Christian Lechat, 23-07-2010 05:08
Christian Lechat
Re:Leptosphaeria ??? on Quercus
Dear Martin,
I don't know what is your fungus but did you consider the genus Melioliphila?
Martin Bemmann, 23-07-2010 11:22
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
Dear Christian,

Thank you for your suggestion! I don't have the literature to check this genus but I have read that it is "Hyperparasitic on superficial foliicolous ascomycetes" (Pirozynski, Kew Bulletin 31 (3), 1977, p. 595).
But this guided me in the right direction, I think: I came across Tubeufia/Acanthostigmella brevispina that seems to be very close though I did not observe spines on the ascocarp and it should grow on old Hypoxylon deustum. But maybe there are other species in this genus that would match my collection.

Best regards,

Martin
Hans-Otto Baral, 03-08-2010 17:42
Hans-Otto Baral
Re:Leptosphaeria ??? on Quercus
I was thinking that I answered from Lapland to this contribution. This fungus seems to be Exarmidium inclusum. Apparently M. Barr identified a collection as such. Cannot tell a literature about it.

Zotto
Martin Bemmann, 04-08-2010 09:18
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
I could not consult Aptroot, A world revision of Massarina, Nova Hedwigia 66(1-2): 140 (1998) since I have no access to this journal (can someone provide it?). But in Sherwood-Pike/Boise, Brittonia, 38(1), 1986, pp. 35-44, where Exarmidium inclusum is treated (as Xylopezia inclusa) I could see that it has smaller ((11.5) 13-16 (17) x 4-6 µm) and and much more fusiform spores than my collection. Other Xylopezia species shown there do also not fit well.

Regards,
Martin
Hans-Otto Baral, 04-08-2010 11:21
Hans-Otto Baral
Re:Leptosphaeria ??? on Quercus
Hi Martin

I see some variation in spore size among the four specimens I have seen, but I feel they belong to the same species (at least same genus).

F.ex.:
*18-21 x 7.3-7.8 µm, 3-septate, 2nd cell distinctly wider,
or *16.2-19.2 x 7-7.7-9 µm (HB 8204b)

Usually the ascomata were perithecioid but in one (HB 6226) apothecioid. 6226 and 6045 are on the DVD, under a name I forgot, perhaps Micraspis or Tarbertia.

Here images from a find from S-Sweden, on Rosa (HB 8204b)
  • message #12474
Hans-Otto Baral, 04-08-2010 11:23
Hans-Otto Baral
Re:Leptosphaeria ??? on Quercus
Here spores in IKI
  • message #12475
Hans-Otto Baral, 04-08-2010 11:27
Hans-Otto Baral
Re:Leptosphaeria ??? on Quercus
Perithecia. I now remember we had this species already in the forum:
http://www.ascofrance.fr/index.php?r=forum&page=viewtopic&id=11375&highlight=exarmidium#msg11382
  • message #12476
Martin Bemmann, 04-08-2010 11:36
Martin Bemmann
Re:Leptosphaeria ??? on Quercus
Yes Zotto,

especially your collection 6226 fits very well to my find. Meanwhile I read Barr/Boise, A Revision of Exarmidium, Mycotaxon 23, 1985, 233-240 and stumbled upon E. diaphanum (Zignoella diaphana). The description fits very well (even by sporesize).
Below I give Berlese's illustration that shows a lentil shaped perithecium as I had observed.

Regards,
Martin
  • message #12477