Observation 170980: Tylopilus rubrobrunneus Mazzer & A.H. Sm.

When: 2014-07-21

Collection location: Hunlock Creek, Pennsylvania, USA [Click for map]

Who: Dave W (Dave W)

No specimen available

Each summer there are multipe frutings of this very bitter Tylo. For some time I had gone back-and-forth between the names rubrobrunneus and violatinctus. Young material has generally exhibited traits consistent with rubrobrunneus… deep purple cap, glabrous brownish stipe with marbled appearance, the occasional specimen with stipe apex reticulate. But KOH reaction were often much different than what is reported for rubrobrunneus.

When they finally showed up last week, I was away from home for a few days. By the time I collected them, they were already mainly post-mature. But the KOH reaction with this batch agrees with the expectation for rubrobrunneus… mainly pinkish/brownish. Photos show the reactions.

Here’s an obs from last year. Note the mustard-green KOH reaction. obs 138813

It’s possible that both rubrobrunneus and violatinctus grow in this same small area where I have made these collections. But I think there’s one species here. If so, then I wonder about the variable KOH color reactions. A couple suggestions to explain this variation are: elapsed time between harvest and reaction-test, age/maturity of specimen. But I think there’s another possible explanation. Perhaps some environmental factor such as frequency/acidity of rainfall plays a role…

Here are some other obses of this type(s) mushroom collected form the exact same location. obs 70102 obs 70441 obs 73784 obs 75583 obs 103651

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Created: 2014-07-23 10:55:09 MST (-0700)
Last modified: 2014-07-23 10:57:14 MST (-0700)
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