Difficulties with Panaeolus and Panaeolina

[Steve]

Hi,

I assumed that SBM 1 (on the left of the photos) – it was growing in a grassy patch in woods – was Paneolina foeneisecii , from its general appearance, especially the banded hygrophanous hemispherical cap. I just picked a specimen to check the spores as routine. However, the spores, although mottled/verrucose, were clearly not right – not rough or angular or big enough. There aren’t many Paneolus with mottled spores – but simply on shape and size I’d say these point to P. ater (fimicola) – Turf Mottlegill. I looked for chrysocystidia on the dried specimen but found none, though they may possibly not have developed.

Later on we found the more Psathyrella-like SBM 2 (on the right of the photos)in a similar habitat, with pinkish brown caps upturned at the rim, and silky white stems which snapped easily – on microscopy they proved to be Panaeolina foenisecii by the characteristic spores. Confused? :

Putting the spores together on a slide showed how different they were:

SBM 1: 11.13 x 6.5-7.5, slightly flattened, oval-lemon shaped, with eccentric germ pore. Clearly mottled/verrucose on high light intensity.

SBM 2: 13-16 x 8-9.5, typical of Panaeolina foeneisecii ie almond-shaped and very roughly warted.

I wonder if some SBM spores don’t get noted as being mottled, as it’s probably only because of the high intensity of my LED that I spotted them? I’d never have spotted them with the old tungsten scope.

Cheers,

Steve

[roy betts]

I’m always having trouble with Panaeolus collections with mottled spores! (and I use a separate bulb as a light source).

Often the mottling seems more obvious with the immature spores which are a paler colour. But then I do get collections which are truly smooth.

According to the BFF5 key the only species with spores “faintly roughened under oil immersion” is P. olivaceus, but it’s spores are 12-15 x 8-10µ and sublimoniform. I have certainly recorded collections under this name.

But your collection with spores more or less ellipsoid and up to 13 x 7.5µ can only be P. fimicola.

This and P. ater are now synonymised. In the BFF5 key they are separate with ater having an oblique germ pore and chrysocystidia and fimcola with a central pore and no facial cystidia (maybe why you couldn’t find any!).

[Steve]

Thanks Roy,

It’s quite fun to watch the confusion developing in the field guides – Bon for example, I think has has 2 of a couple of Panaeolus species (ater/fimicola, rickenii/acuminatus) which are now just one! You try to see where they have distinguished between the two! Hygocybe conica and nigrescens are another pair, over which many people must have agonised in the past – all in vain. But it looks like DNA molecular analysis is going to wreak havoc for us – I think I maybe picked the wrong smiley….

Yes, I’m settling for P. fimicola. I just looked at a Panaeolina foenisecii growing in the lawn outside – it does have a remarkably brittle Psathyrella-like stipe.

Cheers,

Steve

[roy betts]

I assume the conica/nigrescens pair have been DNA’d by now and the argument settled. But what about the two Panaeolus pairs – have they been ‘done’?

As you say DNA analysis is likely to bring some nasty surprises. You’ve only to look at the Paxillus involutus complex and Section Minores in Agaricus to see the trend. We seem to have gone from the Orton era of British mycologists describing new species which have then been lumped together by continental authors only to be split up again following DNA sequencing.

The Genus Inocybe is an example where Kuyper lumped species together which are now recognised as species complexes. I wonder what will happen with Pluteus…

[Flaxton]

I seem to think I heard recently that there are up to TWELVE distinct species in the conica/nigrescens group 😮

Mal

[Chris Yeates]

Flaxton wrote:

I seem to think I heard recently that there are up to TWELVE distinct species in the conica/nigrescens group 😮

Mal

Hygrocybe sensu lato is a classic splitter/lumper group. Interesting open-access paper here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160800/” class=”bbcode_url”>http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3160800/

Chris

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