Observation 13326: Cystoderma Fayod

When: 2008-08-19

Collection location: Jemez Mountains, Los Alamos, New Mexico, USA [Click for map]

Who: Douglas Smith (douglas)

Specimen available

Found under spruce and ponderosa pine.

These are clearly Cystoderma, and I just popped the name C. amianthinum, but that might not be true.

The first micro-shot is of the gill edge at 1000x in Melzers. Here there are no cystidia, and the spores are amyloid.

The second micro-shot if of seom spores from the gill at 1000x in Meltzers. Here the spores are smooth, ellipsoid and amyloid. There were not a lot of spores to measure, but the ave size found was : length – 7.18 +/- 1.37 (err 0.62) um, width – 2.92 +/- 0.18 (err: 0.12) – q : 2.46 +/- 0.46, on 5 spores.

So, it turns out the spore length is significant in this genus. Not the only thing to go on, there are other features, but consistently the spore size will divide the genus up into groups of species. The problem here, is that these spores are larger than any listed in the ref. So, these are not C. amianthinum.

There is a note about a western species published by Smith and Singer in 1945 called Cystoderma gruberianum, with large spores. The spore size they site is 9-11um long, and these spore are smaller than that.

So, not sure which these are. I need to go back to these and get more spores, and look for “arthrospores in the pileus context”, and figure out what those might look like. Also I might need to look up with Monograph of North American Cystoderma, Smith and Singer (1945), except I can’t seem to find a copy of this one anywhere…

Species Lists


1000x in Meltzers, gill edge Lacking cystidia
1000x in Meltzers, amyloid spores over 7um long

Proposed Names

57% (1)
Recognized by sight: Granular cap and stipe, partial veil, white gills.
Based on microscopic features: Smooth ellipsiod amyloid spores, no cystidia.

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= Observer’s choice
= Current consensus


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