Psathyrella help please

[stickman]

Hi all

I was wondering if anyone could double check the following for me?

A Psathyrella growing on woody debris:



Spores on average 10.8 x 5.6 µm:



Pleurocystidia present:



Cheilocystidia covered with green droplets in 40% ammonia:





Keying this out in FN I get to P.narcotica. Obviously I am a little wary to 'officially' give it a name without at least checking it against a reliable photo.

I'm sure there is someone out there (Chris? Ken? Melanie? Anyone?) with some Kits van Waveren literature (or similar) who can please spare a second to glance at the description & illustration to make sure they match up?

Many thanks,
Nick

[Chris Yeates]

Melanie has my copy of Kits van Waveren on Psathyrella on (very) long term loan

over to her

Chris

PS coloured gill edge?

[stickman]

Hi Chris - that was quick

No coloured gill edge - I should also add the smell was faint but unpleasant.

Hopefully Melanie passes by soon.

Cheers,
Nick

[SheffieldLass]

Hi Nick

Keying it through Funga Nordica does take it to P narcotica. So I then did a check with the Kits Van Wavern book but wasn't entirely convinced, particularly as he says cap never micaceus or rugulose, together with the fact that it has very few records in Britain for it. However the other species in the couplet, P jacobsonnii was the less convincing of the two. So, as the green drops in ammonia are a pretty uncommon but distinctive feature I decided to do a search for 'green' in the Funga Nordica key, to check through each one with this feature, because the spore size ranges are overlapping so easy to be looking in the wrong section. P lutensis turns up (actually coupled with P narcotica )in another section of the key. It is without a nauseus smell and without a pseudorrhiza, which are things you hadn't noticed yours having. Also spore size fits in nicely.

So I looked up P lutensis in KvW, and there its cap is described as slightly micaceus and rugulose. Which your appears to be. The stem is supposed to be satiny-flexuous, with white satiny fibrillose layer over the pale redish brown actual surface of the stem. Although your photo doesn't show the stem clearly, it does look rather like that .... The pleurocystidia of P narcotica are drawn as more acutely pointed than those of P lutensis, similarly the cheilocystidia. Though from your photos of the cheilocystidia they could fit either ... What are the pleurocystidia like?

From the info you've given I'd tend to favour yours being P lutensis. Habitat is right. However others may come to different conclusions ...

These are some P lutensis pictured on Bioimages:
Psathyrella lutensis (Romagn.) M.M. Moser ex Bon, 1983 (a brittlestem)
Psathyrella lutensis (Romagn.) M.M. Moser ex Bon, 1983 (a brittlestem)

Melanie

[stickman]

Hi Melanie

Thanks for your comprehensive reply.

Sometimes it's good to have a fresh pair of eyes - I hadn't noticed P.lutensis - despite going over the keys again & again!

It looks like a far better fit than P.narcotica (P.jacobsonii isn't included in the Basidio Checklist)

I think I'll measure the spores again and monitor the smell whilst they dry to be sure, then maybe send them to Kew for confirmation along with this large Conocybe which was on the same pile of debris - it keys out to C.aurea (there's only 2 previous UK records so here's hoping...):



Cheers,
Nick

[SheffieldLass]

Originally Posted by stickman

Sometimes it's good to have a fresh pair of eyes - I hadn't noticed P.lutensis - despite going over the keys again & again!

Cheers,
Nick

I've learnt with the Funga Nordica Psathyrella key that the key steps that are based on the spore size range are not to be relied on. The overlap is too great, and most of the Psathryella species that I find have spores on average very close to, and quite often exactly the same as the figure where you're supposed to decide whether they are greater or less than And I usually measure at least 20 spores. So I tend to end up running through a few sections of the key, just to be sure. And quite often, even with the KvW book to double check everything, fail to reach a conclusion.

I hope the Conocybe is C aurea. Always nice to get a good find!

Melanie

[stickman]

Hi Melanie

Yes I know what you're saying - probably about half of my spore measurements are exactly on that half-way point. Sometimes I think the authors of they key have done it deliberately to wind us up

Cheers,
Nick