Observation 195721: Ganoderma megaloma (Lév.) Bres.

When: 2014-09-05

Collection location: Creve Coeur Park, Maryland Heights, Missouri, USA [Click for map]

Who: Judi T. (AvidAmateur)

Specimen available

Several growing on standing, very decayed tree trunk.


Copyright © 2014 jathomas
Copyright © 2014 jathomas
Copyright © 2014 jathomas
Copyright © 2014 jathomas

Proposed Names

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Thanks again, Herbert.
By: Judi T. (AvidAmateur)
2015-03-25 19:23:12 CDT (-0500)

I truly appreciate your clear, concise, informative, interesting, and always helpful answers to my questions!

Yes, Judi
By: Erlon (Herbert Baker)
2015-03-25 18:33:26 CDT (-0500)

However, between growth cycles the pore surface will dry out and not be writable. The strongest staining will happen with a fresh, moist, pore surface. A good way to preserve the staining is to dry the fungus out completely. Some artwork has been preserved for well over 100 years this way.

Matt, I know we already spoke about this since you asked but I should include that info here as well. The neotype for G. applanatum is from Germany, to the best of my knowledge. There may be a collection of G. megaloma at the Paris herbarium, from New York, under the name Polyporus applanatus. A neotype would still need to be selected for the name G. megaloma as it appears there is no herbarium sample attached to the original description.

Herbert, is the pore surface
By: Judi T. (AvidAmateur)
2015-03-25 17:52:20 CDT (-0500)

on G. megaloma “write-able” as with G. applanatum? I am used to using that feature as a good field observation for making an ID.

Type specimen.
By: Matthew Schink (MSchink)
2015-03-23 18:37:33 CDT (-0500)

Herbert, do you know where the type locality for G.applanatum is? I hopefully have a specimen coming from Germany and I would like to know how close to the type locality it may be. I found a study mentioning a neotype was selected and where the neotype is held, but not where it was collected.

Aslo is there a known type specimen for G.megaloma?

Herbert, your explanation …
By: Judi T. (AvidAmateur)
2015-03-23 18:12:53 CDT (-0500)

makes perfect sense to me. The points you brought up (the tiny pores, the color, the prominent sterile rim on the pore surface) were what I keyed in on originally when I first looked at this specimen. However, having been told just within the last 5 months by other MO experts to call similar observations G. applanatum many of us amateurs have been doing so. Keeping up with all the name changes as a result of DNA testing, etc. is challenging for everyone, I know. I get it, but when someone comes along every few months and gives an observation yet another name and when we see the experts argue among themselves about what to call an observation, we amateurs feel very uncertain about whom to believe.

I just posted a similar observation (#201414) as G. megaloma, based on the all the good information you provided for me this morning. Any bet has to how long it will be before someone (amateur or expert) comes along and proposes that I change the name to G, applanatum? (Ha! Ha!)

Knowing and learning how to identify the fungi is the joyous challenge on which we mycophiles thrive. Having to change those IDs frequently and repeatedly is frustrating. I don’t have any suggestions, but hopefully, the powers that be on MO are addressing this issue. Thanks so much, again, for helping me to learn something new today. And thanks for “cleaning up” some of the backlog of confusion on MO regarding this beautiful polypore.

Hi Judi
By: Erlon (Herbert Baker)
2015-03-23 12:49:39 CDT (-0500)

G. megaloma is typified by its milk white colors becoming dark brown. The sterile band of pores circumscribing the underside margin, and smaller spores. If you click on the name, I have some included a table-key for a couple of look-a-likes in the east, for comparison.

Best wishes,


Thanks for the suggestion, Herbert.
By: Judi T. (AvidAmateur)
2015-03-23 11:13:31 CDT (-0500)

Would you mind educating me by explaining your reasoning behind this change.

Created: 2015-01-06 21:21:59 CST (-0600)
Last modified: 2015-03-23 10:45:28 CDT (-0500)
Viewed: 112 times, last viewed: 2017-06-19 17:35:27 CDT (-0500)
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