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When: 2008-10-03

Collection location: Peace River Area, British Columbia, Canada [Click for map]

Who: Johannes Harnisch (Johann Harnisch)

No specimen available


Copyright © 2008 Johannes Harnisch
Copyright © 2008 Johannes Harnisch
Copyright © 2008 Johannes Harnisch
Copyright © 2008 Johannes Harnisch
Copyright © 2008 Johannes Harnisch

Proposed Names

32% (2)
Recognized by sight: looks like an Oyster mushroom but has a stalk, does not have a veil(ring) and growes in polar tree wounds on living trees
Used references: David Arora’s book Mushroom Demistified, Paul Stamets, Eugene

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= Observer’s choice
= Current consensus


Add Comment
Interpretation is difficult
By: Irene Andersson (irenea)
2009-03-25 03:34:24 PDT (-0700)

I’ve had big problems with ulmarius and tessulatus.

Both were published by Bulliard from France 1791, tessulatus slightly smaller, with a marbled and more reddish brown coloured cap, which was said to be fading. Only a few specific hosts were mentioned – tessulatus on oak timber and old trunks of apple trees (or relatives?); ulmarius on trunks (“sonches”). Btw, the picture of it was named Agaricus tessellatus.

These species were later sanctioned by Fries, who added that ulmarius was found on Ulmus, Populus, Fagus etc.; tessulatus on Quercus and Pinus (miswritten??).

When Singer made the new combination to Hypsizygus, he made tessulatus the type species of the genus. He also stated that the american ulmarius was identical with the european tessulatus, and I guess that’s why american collections were called that for a long time. Now, if these actually ARE synonyms (I suspect that now), I’m not sure what would be the proper name to use, but in Europe, it’s ulmarius now (with tessulatus as a synonym).

The marbled northern species, which I have persisted to call tessulatus and only found on birch so far, I suspect is something else – or just another variety of ulmarius. These have furry stems too..

Hypsizygus perspective
By: walt sturgeon (Mycowalt)
2009-03-24 19:42:03 PDT (-0700)

As I interpret these two Hypsizygus tessulatus is the water spotted one which often grows in clusters. It is common in the Northeast, Lake States, Ontario and the central appalachians. Much less common is H. ulmarius which I see in Algonquin Park in Ontario. It is not markedly water spotted but can be slightly scaley. Both occur on deciduous logs and stumps. The Asian species is something else.

A very good question
By: Irene Andersson (irenea)
2009-03-24 14:59:17 PDT (-0700) presents both species, spore size 5-6 µ in ulmarius, 4-5 µ in tessulatus. The latter is supposed to be a species with a marbled cap, but ulmarius has also been described with a slighly guttulate cap.

The name Hypsizygus tessulatus has lately been used for a smaller species that is commonly cultivated in Asia, and should look something like this (but highly variable in colour and pattern):

I don’t know what to think about this distinction between the two species.
It’s not impossible that H. tessulatus is a synonym to ulmarius, and the asian species actually being another – with names like marmoreus, elongatipes..

What should I look for?
By: Johannes Harnisch (Johann Harnisch)
2009-03-24 14:12:11 PDT (-0700)

I have a microscope but what should I look for next time I find it?

any microscopy done on it?
By: Gerhard Koller (Gerhard)
2009-03-24 05:23:36 PDT (-0700)

it looks like H.ulmarius which I consider to be synonymous but you can’t be sure 100% unless you check microscopy … smooth cap would be okay for H.ulmarius as far as I can say.

Can I be sure of the ID
By: Johannes Harnisch (Johann Harnisch)
2009-03-23 16:31:33 PDT (-0700)

Are you sure I ID this one right?
the cap is smooth does that matter?