Observation 68686: Inocybe (Fr.) Fr.

When: 2011-05-19

Collection location: Sawmill Mountain Rd., Stanislaus National Forest, Tuolume Co, California, USA [Click for map]

37.0° 119.0°

Who: Tom Bruns (pogon)

Specimen available

This Inocybe is distinctive because of its very angular spores (10.1-10.9 X 5.4-6.0), the non-encrusted cheilocystidia, the sparse caulocystidia that are limited to the stipe apex and not particularly thickwalled, and the lack of smell. Cheilocystida have a tapered pedicel at the base and the sizes are 59-63 X 9-11 (apex) with a wall that is 1.5-2 um thick, basidia are four-spored 35 X 10. It may have a very faint farinaceous taste, but its not very noticeable.

In trying to key this out I hit dead ends in the Key Council key and in Brandon Methany’s new key which took me to fuscodisca and lanatodisca, respectively. Both of these species are smooth spored. I tried the Fungi of Switzerland Vol 5, and it took me to I. proximella, which fits in most aspects but the shape of the cheilocystida seems wrong. I used the Agaricaceae of Michigan (Kauffman’s key) and it keyed right to I. decipientoides Peck. The name is still valid and everything seems to fit, so that’s what I’m calling it, but the description in Kauffman isn’t very extensive, and I’d be happy to hear some better suggestions on what this is.

Brandon Methany emailed me the following:
“Hi Tom, Nice find. I know with 100% confidence that this is not I. decipientoides. Though this hasn’t gone live yet on the www, you can find a pretty good description of I. decipientoides here (current name: I. curvipes), including some images.

The overall aspects seem closest to I. decipiens sensu Stuntz, which he recorded under Pinus ponderosa in early June (spring) from the east side of the Cascades (drier interior). I think I found it as well on the east side in May on several occasions. I doubt it’s the same thing as Bresadola’s species, but they share many features in common.

If your material has a marginate bulb or bulbous base, which it may according to your pics, that strengthens the case for I. decipiens sensu Stuntz. Caulocystidia (as metuloids) should be visible on the upper half and/or above the base. They should be mixed with smaller, thin-walled clavate cells, one of which appears in your photo of the caulocystidia, it appears."


spores at 1000X
spores at 40X
Cheilocystidium and basidium
Caulocystidia at stipe apex
Caulocystidia at stipe apex

Proposed Names

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Based on microscopic features: see below in notes

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Created: 2011-06-06 15:57:52 CDT (-0400)
Last modified: 2011-06-06 18:23:26 CDT (-0400)
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