Another load of Lepiotas

On the Sussex Fungus Group foray at Seaford Head (which I wrote about here) we spent some time fossicking about in the strip of scrubby woodland which flanks the eastern side of Hope Bottom. It was here that we came across some charming Dapperling Lepiota -like species: a genus which I was trying very hard to get to grips with the other week. So, in a show of mycological bravado, I offered to take the Seaford Head specimens home to ID.

Happily, via the magic of Twitter, I got some tips from mycologist Andy Overall which has helped; along with some pointers from Nick Aplin. I would have got completely stuck otherwise as working my way through the keys in Funga Nordica has been hard going.

In terms of habitat, they were all found growing in soil in broadleaved woodland (dominated by hawthorn).

And they've all produced white spore prints.

So here's introducing...

Lepiota 1

Suggested ID, based on photo: Lepiota subincarnata

Cap: Pinkish brown, cracking into scales. Paler towards the margin.

Odour: some odour but not distinctive.

Gills: Medium spaced.

Stipe: Cylindrical; widening slightly towards the base. Pinkish; with girdles of colour towards the base.

Spores: Relatively small. All the ones I've measured are around 6 microns. The shape is fairly cylindrical which fits with L. subincarnata. They've turned yellow in Melzers reagent.

1000x magnification. 1 sub-unit ~ 1 micron. In Melzers.

1000x magnification. 1 sub-unit ~ 1 micron. In ammonia.

Pileipellis: The cap is made up of long elements but I've had a heck of a time trying to get a good look at them. There seems to be a mixture of long thin ones and shorter club-shaped ones.

1000x magnification. Stained with Congo Red.

1000x magnification. Stained with Congo Red.

So far these features seem like a reasonable match for L. subincarnata. That species should have club-shaped ('clavate') cheilocystidia.

At this point I realise I should have got my specimen in the dryer sooner than I did, as something's been munching the gills. I've done my best to salvage an in-tact piece of gill, and – after several attempts – I think I've found something that looks like a cheilocystidium.

Cheilocystidia: Clavate.

This has taken AGES. So let's agree that this one's Lepiota subincarnata and move on.

Lepiota 2

Suggested ID, based on photo: Lepiota grangei or L. griseovirens

Cap: Dark grey with grey-black scales.

 

Stipe: Grey, with dark grey-black girdles.

Gills: Medium spaced.

Spores: 9 - 10 microns long with a truncate, spurred base. Stain reddish-brown in Melzers reagent.

Pileipellis: Elongate cells. Not obviously septate.

400x magnification. Mounted in ammonia.

400x magnification. Mounted in ammonia.

I think this might be showing 'incrusting pigment' in one of the pileipellis elements:

400x magnification. Mounted in ammonia.

Cheilocystidia: Irregular cylindrical, utriform to clavate. Loads of them!

These features seem like a reasonable match for Lepiota griseovirens.

Lepiota 3

Suggested ID, based on field observations: Cystolepiota seminuda

Cap: This is a really lovely little thing, with a dusty texture to the cap ('slightly pulverulent'). The margin is hung with ragged veil remnants.


Stipe: Dark purplish towards the base.

Spores: Are teeny weeny! Only about 4 microns long. (The spore print was almost impossible to see on the microscope slide, but I did get one.)

Cheilocystidia: Not present.

I think this confirms this collection as Cystolepiota seminuda.

Lepiota 4

Suggested ID, based on photo: Lepiota brunneoincarnata (?)

Here's what they looked like in situ.

Cap: Young caps a rich, dark brown colour, breaking into (floccose?) patches against a white background. Cap colour paler in larger, more mature fruit bodies.

Couldn't convince myself I could see any 'vinaceous' or purple shades which rather messed things up as far as working through the key goes.


Stipe: Cylindrical. White-cream and finely silky-fibrillose towards the cap. Very pronounced girdles of cap colour towards the base. No ring, or obvious ring-zone.


Gills: Free, crowded.

Odour: Not distinctive.

Spores: Length generally just under 10 microns. Width ~ 3.5 to 4 microns. Shape ~ ellipsoid, or slightly amygdaloid and flattened at one end (truncate). Dextrinoid.

1000x magnification. In Melzers reagent. 1 subunit ~ 1 micron.

Pileipellis: With long, cylindrical cells.

100x magnification.

400x magnification.

400x magnification.

I just managed to make out a clamp connection in this image which rules out a number of species. L. brunneoincarnata has clamps.

400x magnification (close up).

L. brunneoincarnata is also described as 'often septate' (i.e. having a wall between two cells). I  think this image shows the pileipellis elements to be septate.
 

1000x magnification.

Cheilocystidia: Very difficult to see! But I think these are clavate cheilocystidia on the gill edge.

Not sure what this is... A basidium?

In conclusion, it seems plausible that this collection is L. brunneoincarnata. However, two things are bothering me:

1. The lack of a 'vinaceous tinge' to the cap.
2. The shape of the spores, some of which look to me to be slightly truncate and not a perfect match for the illustration in Funga Nordica.

If it's not L. brunneoincarnata I don't know what it is, as I've ruled out various other species including:

• L. pilodes, L. castanea and L. ignicolor – as these Lepiota species are all without clamps.
• L. cortinarius – I thought the spores looked a better match for this species, but L. cortinarius has a clavate or abruptly bulbous base which my collection doesn't.

Maybe I should put this on my Christmas list...

UPDATE 27/10/2017: It seems this mushroom may be something different, so it has been despatched to Dr A. Martyn Ainsworth, Research Leader in Mycology at Kew, for further examination. Hopefully I shall have an update on its identity in due course...

For the record
Date: 14 October 2017
Location: Hope Bottom, Seaford Head
Grid reference: TV508977

Collections retained for Lepiotas 2 & 4.