A pale stalked Myxo appearing on incubation

Not technically fungi, but often lumped together with fungi
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Steve
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Location: Sheffield, Yorkshire

A pale stalked Myxo appearing on incubation

Post by Steve » Sun Aug 07, 2016 11:17 am

Hi,
This Myxo grew on a bit of what we assumed to be Larch wood. It was taken from the end of a log, with a specimen of Orbilia xanthostigma, collected 14/7/16. I spotted it about 3 weeks after collection, in the moist box in which I was incubating the Orbilia. I assumed at first it was a tiny agaric, but it is a Myxo.
The sporangium is approx 1mm, and the stalk also 1mm. The spores are very pale brown , and they seem to be hardly ornamented at all, and are 6-8 um diameter. Removing the spores by blowing and washing in meths showed no columella, just a partly netted rough capillitium with elements about 2-2.5 um wide. I tested the surface with acid and got no effervescence, neither could I see any microscopic evidence of a peridium, so I assumed there wasn’t one, and that no lime was present.
Cells in the stem were up to 20 long and 16 wide.
I have really no idea what this is!
Cheers,
Steve
1 Macro.jpg
Macro images
2 Macro.jpg
Macro images, scale to right in mm
3 Stem.jpg
Stem
4 Spores and capillitium.jpg
Spores and capillitium
5 Stack 600.jpg
Stacked image x600
6 Stack oil aug 6.jpg
Stacked image x1000

Pitufo
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Re: A pale stalked Myxo appearing on incubation

Post by Pitufo » Sun Aug 07, 2016 2:08 pm

Great photos Steve.

Arcyria cinerea or Arcyria pomiformis seem like good possibilities.

http://nefsg.co.uk/arcyria-cinerea
http://nefsg.co.uk/arcyria-pomiformis

If you stain the spores in Lactic Acid Cotton Blue (or other diluted Lactophenol CB), spores of both species have small dots on them (shown in the pomiformis link above).

According to Poulain, A. cinerea sporangia are taller (>2mm) than pomiformis (<1mm). However, moist chamber conditions may affect size, colour and shape.

The size, cells present in the stipe and spore size suggest A.cinerea is more likely. Poulain gives spores of 6-8um for A.cinerea and 7.5 - 8.5 (9) for pomiformis.

Kind regards,

John

Steve
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Posts: 445
Joined: Sun May 17, 2015 8:59 pm
Location: Sheffield, Yorkshire

Re: A pale stalked Myxo appearing on incubation

Post by Steve » Mon Aug 08, 2016 7:23 am

Thanks John,
I will check with the Lactophenol Cotton Blue - how long do you leave the spores to stain?
Cheers,
Steve

Pitufo
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Re: A pale stalked Myxo appearing on incubation

Post by Pitufo » Mon Aug 08, 2016 9:04 am

They should stain almost immediately.

Lactophenol Cotton Blue is almost too strong a stain to see the dots - the whole spore may go a strong blue colour (Lactic Acid CB stains more weakly, so highlights the dots).

I have never tried it, but I imagine a diluted solution of Lactophenol CB may work just as well.

I can send you some Lactic Acid CB if you need some - it's much less corrosive and nicer to work with.

Cheers,

John

Steve
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Posts: 445
Joined: Sun May 17, 2015 8:59 pm
Location: Sheffield, Yorkshire

Re: A pale stalked Myxo appearing on incubation

Post by Steve » Mon Aug 08, 2016 9:22 am

Thanks John - that's very kind of you,
I suspected that Lactophenol CB would be problematical as it very difficult to interpret when doing Corticioids - in fact I have more or less given up using it.
I have another CB reagent which might work,
Cheers,
Steve

NB just posting a Cyphelloid fungus :)

Steve
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Posts: 445
Joined: Sun May 17, 2015 8:59 pm
Location: Sheffield, Yorkshire

Re: A pale stalked Myxo appearing on incubation

Post by Steve » Mon Aug 08, 2016 10:48 am

Hi John.
I tried the spores with Lactophenol CB dilured a lot but it's still too strong.
I then used some 1% CB in water (rather brown looking so maybe old) and it shows dots nicely.
From re-measuring the (dead) spores they are small and so look like A. cinerea.
Cheers,
Steve
1 cb lp oil.jpg
Diluted Lactophenol CB focus 1
2 cblp oila.jpg
Diluted Lactophenol CB focus 2
3 cblp oilc.jpg
Diluted Lactophenol CB focus 3
4 cb wat oil.jpg
CB in water focus 1
5 cb wat oil2.jpg
CB in water focus 2

Pitufo
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Joined: Thu May 21, 2015 10:18 am

Re: A pale stalked Myxo appearing on incubation

Post by Pitufo » Fri Aug 12, 2016 3:55 pm

Hi Steve

Yes, it looks good to me.

Kind regards,

John

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