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12-04-2026 17:56

Hardware Tony Hardware Tony

Found on dead stems in February earlier this year

12-04-2026 15:52

Gernot Friebes

Hi,I'm looking for help with this anamorph collect

12-04-2026 12:22

William Slosse William Slosse

In a dune grassland in Oostduinkerke (Belgium), on

11-04-2026 15:45

Zuzana Sochorová (Egertová) Zuzana Sochorová (Egertová)

Please, could anyone send me this paper?Moyne G.,

11-04-2026 13:34

Artem Ptukha

Hello, I am seeking assistance with the identific

11-04-2026 10:42

Castillo Joseba Castillo Joseba

Me mandan el material de Galicia, España, recolec

11-04-2026 10:19

Michel Hairaud Michel Hairaud

Chers amis d'Ascofrance , voici une très bonne no

11-04-2026 10:10

Michel Hairaud Michel Hairaud

Dear Ascofrance members, here is some very good ne

10-04-2026 23:22

Gernot Friebes

Hi,ascospores are 1- to 3-septate, approximately 

10-04-2026 15:51

William Slosse William Slosse

Hello everyone, On 08/04/26, I found a growth sit

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Orbilia sp. on Typha
Chris Yeates, 30-09-2014 21:49
Chris YeatesBonsoir tous
today I collected a few scattered apothecia of a discomycete which was difficult to see as it had the same pale brown colour as the surrounding stem of Typha latifolia.

Under the microscope it was clear that it was an Orbilia (with the characteristic knob-topped paraphyses). Inside the asci the spores were clearly long-cylindric and curved with short spore bodies at one end (half the spores reversed). Unusually for an Orbilia, in my limited experience, in a water mount there were many free spores. These were very much curved, some almost into a semicircle - I wonder whether the tension to form this shape contributed to the ease in which so many were ejected in the water mount.

Here are some preliminary images - I can post more in due course, but these are typical. The spore measurements were made from spore tip to spore tip, so they are like the string on a bow, rather than an attempt to measure them along the curve. Measurements made so far are in the range 8.1-10.9 x 1.2-1.3(1.4)µm.

I note there is an Orbilia arundinacea listed as occurring on monocot's like Typha; but looking at the protologue in Velenovsky (1934) he says of the spores 'Sp. . . . rectae' and no spores seen could be described as anything near straight. I cannot find O. arundinacea in Zotto's images - maybe I have missed something.

As ever, help very much appreciated.

Cordialement
Chris
  • message #31519
  • message #31519
  • message #31519
  • message #31519
  • message #31519
Hans-Otto Baral, 30-09-2014 22:16
Hans-Otto Baral
Re : Orbilia sp. on Typha
Hi Chris

this would require a section of the margin, in order to see whether it is a nematode-trapping species or not, and conidia :-)

O. arundinacea is a synonym of O. rectispora - typical for Typha and the like, but, as you say, with rather straight spores.

It is sometimes that you have many free spores in Orbilia. Difficult to explain. But the spore curvature which is actually less so inside the ascus - logically - can hardly contribute to this. The spores are agglutinated in one packet prior to discharge, and the packet is ejectd as one entity.

Zotto

Zotto
Chris Yeates, 30-09-2014 22:28
Chris Yeates
Re : Orbilia sp. on Typha
Thanks Zotto for the quick response - and there was I thinking such distinctive spores might make it easy!

I have little material to work with but I shall have a go at the section, probably tomorrow. What am I looking for in the margin which would tell whether it is a nematode trapper?. I have seen no evidence of conidia but will have a very careful look.

Chris
Hans-Otto Baral, 30-09-2014 22:34
Hans-Otto Baral
Re : Orbilia sp. on Typha
Orbilia auricolor has just those spores, and it is a collective species with an Arthrobotrys anamorph, trapping nematodes by adhesive networks. However the spores are more tapered at the basal end  in O. auricolor, so we are a bit reluctant.

Another option would be O. sambuci = O. fimicoloides, a lkewise plurivorous species with a Dactylella anamorph and no trapping capabilities. The Dactylella conidia are very characteristic: very large, fusiform, multiseptate.

The marginal excipulum forms distinct cell rows under a low angle in those with Dactylella, but roundish cells oriented under a high angle in those with Arthrobotrys.