Observation 5364: Armillaria mellea (Vahl) P. Kumm.
When: 2007-12-09
Collection location: Ottumwa, Iowa, USA [Click for map]
No herbarium specimen

Notes: Several of this species found mid-late autumn in a lawn in Southeast Iowa. Unsure of the species or of edibility. Please identify.

[admin – Sat Aug 14 02:04:18 +0000 2010]: Changed location name from ‘Ottumwa, IA Wapello Co’ to ‘Ottumwa, Iowa, USA

Proposed Names

69% (5)
Eye3 Eyes3
Recognized by sight: Clustered growth, white spores, brown caps.
-10% (4)
Recognized by sight: Based upon decurrent gills, general morphology, and tight cespitose growth, appressed fibrils on pileus.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
Armillaria sp.
By: Michael (dugie)
2008-05-06 00:09:25 BRT (-0300)

One thing I’m noting in the keys… the presence of a sticky cap in A. mellea. In all the fruitings I found last year, I never noticed this, in young or older bodies. Additionally, I would likely recall the presence of prominent annuli on the several specimens, but I did not (not that months of recollection can’t fail me).

Also noting, as was pointed out, how much of a pest this genera can be. No cure it’s said, and one can only hope that the tree and the fungus can coexist. Would hate to have that huge maple succumb, as it’s hovering precariously above my house!

Armillaria (aka Honey Mushrooms) for sure…
By: Nathan Wilson (nathan)
2008-05-05 19:51:49 BRT (-0300)

It is pretty clear that it has a white spore print and that it’s an Armillaria. It would be interesting to know for sure that it has an annulus. Armillaria in general are fairly opportunistic parasites, especially A. mellea. Here in California it is often called Oak Root Fungus and given the right conditions they will attack and ultimately kill almost any tree or shrub.

A. mellea?
By: Michael (dugie)
2008-05-05 18:14:34 BRT (-0300)

Trees growing in the area:
– Silverleaf maples (found several fruitings growing under/around a large tree and by far the most populus tree in the acreage
– various Prunus sp (apple, pear, etc…)
– Elm
– Green Ash
– Catalpa
– Crataegus
– Dogwood

I will attempt this fall, to get better pics of the stipes to more definitely identify presence/lack of an annulus, and perhaps get a spore print (though I’m guessing the color to be white, given the gregarious nature of the fruitings).

I’ll go with Tom’s opinion
By: Nathan Wilson (nathan)
2008-05-05 01:10:40 BRT (-0300)

Given that Tom literally helped write the book on our current understanding of Armillaria, I’m dropping my support for A. tabescens as a possibility.

Armillaria mellea
By: Tom Volk (TomVolk)
2008-05-04 21:46:32 BRT (-0300)

There are a couple things that lean me toward A. mellea. First the aspect of the mushrooms shown here is that of A. melea. A. tabescens is typicallymore cartilaginous and a lot smaller. Second the time of year in Iowa in mid-late fall suggests A. mellea also. I am not bothered by the seemingly lacking ring on the one upturned specimen. The ring is membranous and can be easily be rubbed off. Also given the old condition of these fruiting bodies (as evidenced by the abundant sporulation), the ring often is the first thing to degrade. I still think it’s A mellea, but the main thing, then, is that we can’t really know which species this really is without seeing more of the stipes.

A. tabescens
By: Nathan Wilson (nathan)
2008-05-04 08:19:29 BRT (-0300)

The key feature with A. tabescens is the lack of a ring. The one overturned cap in the photo looks like it might have a ring, but I’m not sure. I’ve never collected A. tabescens (it doesn’t really occur in the western US), so I’d have to defer to those who have to make the call.

Agree with Armillaria…
By: Nathan Wilson (nathan)
2007-12-10 03:45:47 BRST (-0200)

… but I’m not sure about the species. A. mellea seems unlikely given the slight ring visible in the overturned cap and the scales on the cap. However, I’ve never collected in Iowa, so I don’t feel qualified to even guess the species. It would be helpful to know what sorts of trees are growing in the area.

Assume it is an Armillaria, then they are edible. However, I do not recommending eating anything based solely on an id based on a photograph. If you are really interested in eating mushrooms, you should find a mushroom club (look for the club list on the NAMA site) and talk to folks who really know the mushrooms of your area.

By: Joshua Birkebak (Shua)
2007-12-10 00:36:04 BRST (-0200)

Well this looks alot like a gigantic fruiting of Armilaria mellea the Honey Mushroom.. It is hard to be sure though! what do you think?

Created: 2007-12-09 19:54:58 BRST (-0200)
Last modified: 2011-09-29 20:35:07 BRT (-0300)
Viewed: 112 times, last viewed: 2016-10-23 15:02:20 BRST (-0200)