Observation 6971: Pleurotus ostreatus (Jacq.) P. Kumm.
When: 2008-03-02
No herbarium specimen

Notes: Here’s an odd one for y’all…
white gilled, fleshy woodrotter (on hardwood). Central stipe. Decurrent gills (heavily munched by maggots in photo). Cap hemispherical when young, dimpled at all ages. DARK SPORE PRINT. Oddly shaped spores, like sausages or rods or really huge bacteria. Micrograph attached (my first!).

Proposed Names

47% (2)
Recognized by sight
63% (2)
Recognized by sight: Add this as a possibility since that seems to be the best candidate name we’ve come up with (see comments). The spore color is a bit of a concern. Hopefully someone will find other specimens of P. dryinus and provide spore print photos for comparison.
74% (3)
Eye3 Eyes3
Recognized by sight: Hardly! But now I do.
Used references: The fine posting crew at MO; thanks to all.
Based on microscopic features: Spore shape certainly one of the keys.

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Common mushroom, uncommon appearance.
By: Debbie Viess (amanitarita)
2008-03-10 10:21:32 CST (-0500)

I am confidant that this puzzling little fungus is just an unusual Pleurotus ostreatus.
Reasons: whitish fruit body, with decurrent gills, on wood; stipe is rarely central in this fungus, but can be if the mushroom grows from the TOP of a log (check).
Spore print is NOT always white, but can be a dusky gray lavendar (check).
Spores are cylindrical/ellipsoid (check).
Pleasant fragrance, at least back when it was fresh (check).

Thanks Walt, you nailed it. Another reminder that even the most familiar of mushrooms can fool you!

Pleurotus, fer sure…
By: Debbie Viess (amanitarita)
2008-03-09 19:06:12 CST (-0500)

Does ostreatus have a central stype and cylindrical spores? A dusky gray sporedrop with a lilac tinge could fit…

Pleurotus ostreatus complex
By: walt sturgeon (Mycowalt)
2008-03-09 18:33:23 CST (-0500)

The dark spores are typical of some oyster mushrooms. Pleurotus ostreatus has dingy gray spores with a lilac tinge.

Do you know what type of hardwood?
By: Nathan Wilson (nathan)
2008-03-07 16:06:49 CST (-0500)

I’ve most often seen P. dryinus on madrone (Arbutus menziesii). How do you know the cap was campanulate when young? Were there other specimens or did you see it before it got munched?

Pleurotus dryinus? maybe…maybe not
By: Debbie Viess (amanitarita)
2008-03-05 22:20:14 CST (-0500)

Pleurotus certainly fits the general gestalt, woodrotting status, etc. Dryinus has a central stipe, so that fits too. No evidence of a partial veil, tho, altho our little squirmy friends were hard at work on that specimen before we hit the scene. Spore shape fits too (RogersMushrooms calls them cylinders, and I would, too) but…the spores aren’t white. Not really pink either, kind of a dusky pinkish brown (dark as opposed to white, which they weren’t). It’s frankly a miracle that we got any spore drop at all, considering how much gill tissue was missing (if you look carefully at the spore drop photo, you can see the white of the paper where I scraped spores off. We are definitely narrowing the field, tho… keep convincing me.

Maybe Pleurotus dryinus
By: Ron Pastorino (Ronpast)
2008-03-05 17:35:58 CST (-0500)

Pinkish would make more sense and it does look a little like an old beat-up Pleurotus dryinus. The spores are described as “elliptical” but with measurements of “9-12 X 3.5-4 microns”, oblong would seem to be more apt and seem to be close in shape to those in the photo.

Pinkish spore print?
By: Nathan Wilson (nathan)
2008-03-05 16:53:42 CST (-0500)

In the description you say “DARK SPORE PRINT”, but that looks pinkish to me. If it is, then Pleurotus is a possibility.

By: Douglas Smith (douglas)
2008-03-05 12:23:12 CST (-0500)

Don’t know, when I first saw the photo, I thought, oh thats a Clitocybe. But not with a brown spore print. But as brown spores and on wood, that kinda points to Pholiota? It would be good to know if the spores are amyloid or dextrinoid, and if they have a germ pore. They don’t quite look like they have a germ pore there… (Actually I was thinking the spores most look like Lepiota magnispora in shape, or maybe also Boletus? Neither of which make sense, but that is what the spore shape suggests maybe?). Then also what is the character of the cap surface, it doesn’t quite look like a cutis…

Just tossing out random ideas here…

Created: 2008-03-05 10:37:54 CST (-0500)
Last modified: 2008-03-10 10:22:21 CST (-0500)
Viewed: 87 times, last viewed: 2016-10-27 02:30:49 CDT (-0400)