Observation 63573: Pluteus petasatus (Fr.) Gillet

When: 2010-07-12

Collection location: Akademgorodok, Novosibirsk, Russia [Click for map]

Who: Tatiana Bulyonkova (ressaure)

Specimen available

The largest Pluteus I’ve found so far in our area. I must confess I’d thought it was a big pale P. cervinus and put it in the “edible” section of my basket and by the time I’d realized it was “of research interest” there was not much to keep as a specimen, a dirty, well-traveled section of the cap is all I’ve got ;) I regret it bitterly now that I’ve taken interest in the Pluteaceae as a training ground for my little Amanita project (Rod’s awesome new Amanita methodology requires high microscopy skills… which I haven’t got… yet).

Anyway, here are some pictures. There’s one interesting detail – some of its pleurocystida are thorny, there are sharp small projections here and there on their surface. If anyone knows whether it’s normal or not please tell me because I haven’t seen any mentioning of it in the literature.

I didn’t find any clamp connections in the specimen. Cheilocystidia were very scarce and unimpressive, lightbulb-shaped, just like the paraphyses, which, on the other hand, were very numerous and large, especially towards lamella edge. Pleurocystidia were more or less standard for the species apart from the “thorns” issue – thick-walled, horned, relatively narrow. Pleurocystidia near the lamella edge were quite small and just acutely pointed, without the horns.

I only had a small intact piece of pileus surface and it was also standard, made up of clamp-less “spahghetti” with long, mildly pigmented terminal elements, quite similar to those of P. cervinus but a bit thinner. There was a bonus with this particular specimen, too – it was covered with all sorts of “alien” spores, including some germinated mold spores and a big batch of spiny spores which must’ve belonged to a Russula; I found several pollen grains, too. Contamination is fun sometimes.

Species Lists



Proposed Names

83% (1)
Eye3 Eyes3
Recognized by sight: I’m quite skeptical about the id – young fruitbodies don’t look like P. petasatus at all. I suspect these could be oversized P. cervinus just as well. Or something else….
Used references
Based on microscopic features

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
No one has commented yet.

Created: 2011-02-17 17:29:16 CST (-0500)
Last modified: 2011-02-17 17:48:00 CST (-0500)
Viewed: 285 times, last viewed: 2018-12-01 04:05:57 CST (-0500)
Show Log