Observation 13071: Armillaria gallica Marxm. & Romagn.
When: 2008-10-22
No herbarium specimen

Proposed Names

61% (2)
Recognized by sight
79% (1)
Recognized by sight: typical shape, especially with the fibrils on the top. Could be A. clavescenes, but so far impossible to tell, even microscopically or with DNA.

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Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Dan Molter (shroomydan)
2008-11-08 12:48:44 CST (-0500)

Thanks for posting that article Tom. It was very enlightening.

It seems to me the morphological and the biological species criteria intersect at the level of molecular morphology, because mating compatibility is a dispositional property determined almost entirely by the shapes of DNA and other molecules within a cell.

When we look at the properties of something like sugar, for example, sweetness and solubility are properties that only have meaning in relation to some other thing. Sugar has a disposition to dissolve when placed in contact with water, and it has the disposition to cause sensations of sweetness when placed on a person’s tongue. However, the solubility and sweetness follow directly from the molecular structure of the sugar. One could predict the solubility or sweetness of a substance, without dissolving or tasting it, merely by mapping its molecular morphology. Dispositional properties can be cashed out as morphological properties.

Mating compatibility is a dispositional property that follows directly from the molecular morphology (DNA, enzymes, etc.) of the two organisms. So if one understands the molecular dynamics of breeding compatibility within a certain class of mushrooms, then one could potentially define biological species with molecular morphological characters; it would just be a matter of discovering the right characters.

A wrinkle with dispositional properties though: environmental factors affect a thing’s disposition. Sugar’s disposition to dissolve in water varies with the temperature of the water. Just as sugar more readily dissolves in hot water than in cold, it seems likely that variable environmental conditions (temp, PH, nutrient concentrations…) might produce variability in mating compatibility.

A large number of mating tests would have to be conducted under many different environmental conditions in order to properly understand the compatibility between two specimens. A handful of negative tests might not indicate incompatibility.

What about obs. 4603
By: Douglas Smith (douglas)
2008-11-01 12:40:55 CST (-0500)

Well, what about my obs. 4603 from northern CA? We kinda slapped the name A. gallica, because they were found alone or just paired, with a bulbous stipe.

(Also, if I can get you to go that far, I’ve always wondered what you might think of the Armillaria we see up in the Santa Cruz Mnts. here, I’ve got photos for obs. nums 991, 1072, 4792, 4897. I know, I’m just trying to be pushy…)

By: Tom Volk (TomVolk)
2008-11-01 12:22:42 CST (-0500)

Hi Debbie. We have collected A. gallica on the Olympic peninsula, but it looks quite different there. So far no reports of it from CA or OR or anywhere else west of the great plains. weird

do we get gallica out west, Tom? it’s a handsome honey…
By: Debbie Viess (amanitarita)
2008-10-31 09:11:03 CST (-0500)
different biological species
By: Tom Volk (TomVolk)
2008-10-30 21:14:28 CST (-0500)

They don’t mate with one another, so they are considered to be diffferent biological species. They must have recently diverged, changed in their mating genes, but not in their morphologies. We always assume evolution is done, but here is an example where we are right in the middle of it. See this page for more info on biological species.

impossible to tell?
By: Dan Molter (shroomydan)
2008-10-30 20:05:14 CST (-0500)

If it is not possible to distinguish between A. gallica and A clavescenes, even by micro or molecular comparison, then why suspect they are different species?

Created: 2008-10-24 21:03:49 CDT (-0400)
Last modified: 2008-10-24 21:03:49 CDT (-0400)
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