Observation 25538: Boletinellus merulioides (Schwein.) Murrill
When: 2009-09-19
No herbarium specimen

Notes: Mycowalt told a neat story about this mushroom at the Ohio gathering a few weekends ago. Supposedly the ash bolete grows on honeydew from aphids that suck sap from the roots of ash trees.

Michael Kuo tells a similar story:
http://www.mushroomexpert.com/gyrodon_merulioides.html

I noticed a few things the other day that makes me suspicious of the accuracy of this story.

I did not find any aphids around these mushrooms, even though I examined quite a few of them. I only found the little black blobs shown here. Kuo says the blobs are sclerotia that surround the aphids, but if the aphids are completely encapsulated in sclerotia, then how can they bite into the roots? Furthermore, none of the black blobs I observed appeared to be attached to roots. On top of all that, some of these mushrooms were growing from rotted wood, several inches above the ground. Above-ground rotting wood is not the kind of place were one would expect to find aphid infested tree roots; I found neither aphids nor roots in the rotting wood.

I wonder if something more complex than the received story is going on here.

Images

57537
57538
57539
58386
This ash bolete is growing from a rotting log several inches above the ground. This seems an odd place to find a mushroom that is supposed to feed off the honeydew of aphids attached to the roots of an ash tree.

Proposed Names

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

Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

Add Comment
Interesting
By: Martin Livezey (MLivezey)
2011-12-18 12:04:00 PST (-0800)

I am determined to examine the same next time I find this specimen. Did you slice open the black blobs? That is missing from your story. Maybe there are little guys in there. I guess another approach would be to do DNA analysis on the black blobs. Maybe there are bacteria involved in the creation of them – like the nitrogen fixing bacteria on alfalpha.

great pix of sclerotia
By: Tom Volk (TomVolk)
2009-09-23 20:28:00 PDT (-0700)

Good job! I don’t know the whole story of how this fungus gets it nutrition.

tiny roots
By: Dan Molter (shroomydan)
2009-09-21 15:56:02 PDT (-0700)

maybe there are tiny roots showing in the first photo

Created: 2009-09-21 15:48:39 PDT (-0700)
Last modified: 2011-12-18 09:26:49 PST (-0800)
Viewed: 216 times, last viewed: 2017-01-02 16:54:08 PST (-0800)
Show Log