When: 2007-10-01

Collection location: Sonoma Co., California, USA [Click for map]

Who: Douglas Smith (douglas)

Specimen available

A mushroom brought in tonight for the mycology class, and we couldn’t place it. It certainly looks like a Leucoagaricus species, but not one anyone knew. Also the stipe displayed red staining when bruised, although very slowly. It seems that the red staining turned grey in time. The cap seems to be more grey than L.leucothites, although the cap is smooth like that one. And that one doesn’t have a staining reaction. The cap isn’t fibrous enough for L. barssii, and anthough that one is grey, it doesn’t stain either.

So, I’ll put it here to see if anyone has a better idea. Also I popped them in the drier for more study later, or if anyone wants the dried samples here.

Ok, more details, did some microscopic work on the dried material this week.

The first microscopic image is of a gill, laid flat and mounted in Meltzer’s reagent, and taken at 400×. The divisions are 2.5 microns in the scale. The spores have a funny staining reaction, it looks like some stain red-brown, some lightly reddish, and some not at all. The ones not staining seem to be the attached ones, so it looks like that spores only stain in Meltzer’s when mature. Does this happen? It isn’t something I knew about, but I’m pretty new to this whole microscopic thing…

The second image is the same mount, but of the gill edge, also at 400×. This shows the cheilocystidia as the clear un-stained cells.

The third image is the same mount, but of a group of spores, at 1000x times under oil immersion. The divisions are 1 micron in the scale. The spores show a germ pore is present. A few in this photo are in focus enough to see the apiculus, off-center at one end, and the small germ pore, centered at the other end.

The forth image is of the pileipellis (the surface of the cap), and this was mounted in KOH, and taken at 400×. The grey color of the surface cells can be seen here slightly, and the cap trama cells are thicker without color (at the bottom of the image). The pileipellis here looks to be a cutis form to me, but like I said I’m new at this.

I had an e-mail from Else Vellinga about this, and she told me to look for the germ pore and if it has a cutis. With a germ pore, and no cutis – L. leucothites, without a germ pore and a cutis – L. barssii. But this, I think has a germ pore and a cutis, so what is that? But I might be completely off here…

More conversation with Else here, and because of the germ pore, that puts this one into the L. leucothites camp. She also mentions that in Europe there are more species recognized with grey and staining forms (I think…), but it is all L. leucothites here. She stated that this one has “no taxonomic value”, oh well. So, there is a slow, slight red-staining, grey, varient to L. leucothites out there, for people to keep in mind.


Proposed Names

Please login to propose your own names and vote on existing names.

= Observer’s choice
= Current consensus


Add Comment
No one has commented yet.