Observation 224372: Hysterium Pers.

On bark of Eucalyptus globulus.

Spores 3-septate, slight constrictions at septa.

Species Lists


3-septate spores. 1000×. Measurements not taken.

Proposed Names

1% (2)
Recognized by sight
46% (2)
Recognized by sight
28% (1)
Recognized by sight

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I would call these spores “dark”
By: Jason Hollinger (jason)
2015-12-06 13:49:58 ACDT (+1030)

In particular, it looks like the middle two cells are darker than the end cells, a feature I frequently see in Hysterium (is that what the reference you sited means by “versicolor”?). Also, my photos of Opegrapha spores show distinctly thick cell walls — evenly thick, but not too thin to see as in your photos — and furthermore not constricted at all at the septae. I think we can feel confident calling this Hysterium.

…But then again you’re the one with the specimen in hand. I remember a certain observation of a Caloplaca where I turned out tobe wrong no matter how obvious I thought it was in the photos! :)

Microscopy Added
By: J-Dar
2015-12-06 09:38:36 ACDT (+1030)

But I still don’t know what it is! 3-septate spores look a lot like Hysterium, particularly Hysterium pulicare, however at least one species of Opegrapha has spores that appear very similar, O. herbarum, see Zaca’s observation 216512. I wasn’t able to measure spores today, but I will next week, if needed.

http://www.eboehm.com/hysterium.html for info on Hysterium.

Stay tuned…
By: J-Dar
2015-12-05 12:18:10 ACDT (+1030)

Specimen and microscope are at my office, so it will have to be next week. Thanks for the info, never a dull moment here!

spores should be most obvious
By: Jason Hollinger (jason)
2015-12-05 12:06:35 ACDT (+1030)

surprisingly hard to be sure no photobiont is present!

What should I look for first?
By: J-Dar
2015-12-05 12:01:27 ACDT (+1030)

To see if it has a photobiont?
Then spore anatomy?

I agree with Jason;
By: zaca
2015-12-05 11:45:02 ACDT (+1030)

It looks very much like Hysterium, though it could be Opegrapha. I would recommend microscopy to decide.

Hopefully I’m wrong…
By: Jason Hollinger (jason)
2015-12-05 11:14:09 ACDT (+1030)

but I bet this is unlichenized. There are a few genera of pyrenomycetes which produce these big carbonized superficial elongate “perithecia” (?). See, for example, Hysterium.

Created: 2015-12-05 10:39:38 ACDT (+1030)
Last modified: 2015-12-08 12:41:08 ACDT (+1030)
Viewed: 98 times, last viewed: 2019-06-20 21:19:29 ACST (+0930)
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