a Russula - - - Probalby Russula crassitunicata

Posted by Elmer 11/19/12 - - - - - - Scroll Down to see the discussion

Growing on wood
cap convex
Gills Adnate
Spores are white and definitely spiny
Stem breaks but not clean like chalk
.............Scroll Down For More Pictures and to see the discussion..........


It was growing on a stump under Doug Fir

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Cap is convex.

Note the mushroom on the right end is at least a different species


Stem breaks but not quite like chalk


Gills are adnate


Gills are NOT saw tooth


Spore Print is white,
this image is on a black paper background


Spores are definitely spiny
They are round
6 to 7 Microns

Elmer: Is this a Russula?
stem does not quite break like chalk (see picture)
It is white, growing on wood under Doug Fir,
with a convex cap, adnate gills and spiny spores.

Sava: Nice microshot, Elmer! It is a Russula; Judy might even know the species.

Elmer: What does one call the type of break this stem shows.
Sally gave it a name in the last class we had,
but I do not remember what she called it.
It is not quite like a chalk break

Judy: "Yes, it does look like a Russula, and depending on the cap skin characters,
and taste (just a little bit on the tongue will tell you, and no, it won’t poison you)
can determine the species. In these really white Russulas, the cap skin will peel,
and how much toward the center, plus how rubbery it is determines whether it is
R. farinipes (slightly rubbery, peeling 1/4 to 1/3 of cap diameter) and bites back when
you taste it –quite hot and peppery; or if cap skin thicker, peeling at least half way or
more, it is probably R. crassitunicata. This sp. can have brownish spots of flecks on the
stem when older. It usually is a good sized sp. as your photo shows. R. farinipes generally
stays really white, has a more gracile (slender, more fragile) stature, crumbling more than
clean breaks, and has some cap margin striations, and is hot like cayenne peppers.
R. cremoracolor is also hot, larger like crassitunicata, cap peels a bit, and cap
surface creamy, almost yellowish, and stem firm but breakable, looking more dry.
Your photos are interesting and quite good. In the first one, the “line-up”
shows the peel-ability of the cap surface, and with the spotting on most of
the specimens thinks it R. crassitunicata. Your end specimen is some other species
and also probably a different genus too.

In close looks at the stipe, tho they are broken, the outside of them has the dry denseness
of R. crassitunicata as well. R. farinipes has a more watery-looking, almost translucent-looking
stipe surface, even when dry.

The only way to tell for sure is to use Melzers’ on the spores to compare drawings
of the spines and ridges between these, and look at the cystidia –
some have longer roots that go deep in the fleshing, showing their close affinity
with some of the Lactarius genus.

...stipe breakability questions. Russula stipes usually break like the blackboard chalk our
teachers used – the fatter kind, not the skinny kind. But if weather is wet, then all bets are off,
because the mix of cell types (both longer narrow hyphae plus the rounded, inflated
cells that create its breakability, absorb a lot of water. But your photo shows that there
are no long strings of hyphae, such as you would find in a Pholiota or Tricholoma.
Some of the descriptive terms used in the keys are very general, and are not absolute
for all species within a genus.

Additional Pictures - Click on a Thumbnail to see a larger image