When: 2010-02-01

Collection location: Menlo Park, California, USA [Click for map]

Who: Douglas Smith (douglas)

No specimen available

Found under live oak, pine.

Proposed Names

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= Observer’s choice
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Not to mention
By: Irene Andersson (irenea)
2010-02-26 08:31:37 PST (-0800)

the viridilutescens/subsejunctum/luridum complex – and terreum/myomyces..

Yeah, among others…
By: Douglas Smith (douglas)
2010-02-26 04:31:06 PST (-0800)

Yes, T. saponaceum does seem to be be rather too variable. But I’ve seen quite a bit of variation on ones found on the same spot from year to year, so not sure what to do with that.

All the brown Tricholomas I’d believe that they are hard to fully define. But the question becomes what are the features that are important, such that can tell what is a different species or not? People are probably assuming you need to carefully document features and then compare with DNA studies. Is anyone really doing that? Or are they just grabbing stuff from herbarium, ignoring any features at all, and just documenting some random DNA…

I guess Noah here would add to the list T. aurantium and T. portentosum.

Tricholoma flavovirens
By: Irene Andersson (irenea)
2010-02-26 04:11:44 PST (-0800)

is supposed to be a younger synonym of T. equestre, but it has been a lot of confusion about the names and how they should be applied. The sturdy and deeper yellow ones have also been called T. auratum, but are included in T. equestre.

Here is what they write in Funga Nordica about Tricholoma:
“Several species complexes are in need of further studies to be resolved taxonomically; this is e.g. the case for the taxa around T. saponaceum, T. equestre and T. pessundatum.”

Well, this does seem to be a variable species.
By: Douglas Smith (douglas)
2010-02-26 03:47:43 PST (-0800)

I mean in the stuff I seen all in the same place year after year, there is variation in size, stature, a range of colors. But the colors tend to be a range of yellow, green, and brown on the cap, sometimes all of one, or another; yellow, white, and tan on the stipe, with some darkening from the base. But the gills tend to always be a smooth yellow from stipe to margin, I guess sometime a lighter yellow, sometimes deeper.

A lot of it seems to be environmental. I usually find these buried, and I have to dig them up. Even the ones with long stipes. I think these were mostly buried when I found them. The amount of brown seems to be from the exposure to air.

Wasn’t the stuff from France called T. equestre? Did I figure out if those were called the same a T. flavovirens in the past or not? I can’t remember.

But there seems to be quite a bit of variation even within species. And as with other stuff it seems, the molecular work suggests there are multiple species, that look the same? To bad they don’t do the careful work on the features of the samples they determine, so we could start to tell what feature that will be diagnostic or not…

I still say I get to call these T. flavovirens…

By: Erin Page Blanchard (CureCat)
2010-02-26 03:27:39 PST (-0800)

Unfortunately, they didn’t tell what the different collections looked like.

Don’t you just hate that?
If only they were linked with a corresponding MO observation…

I’d vote for flavovirens after all
By: Irene Andersson (irenea)
2010-02-26 03:17:21 PST (-0800)

It’s a complex with lots of forms. I have seen them vary from stout and with rather strong yellow gills and stem (I’ll add two of my obses), to much paler and slender ones, and often wondered if they really were the same species.

When the fatal poisonings occured in France, the question was raised if they were caused by a certain local species (and then it also happened in Poland..), but I haven’t seen any extensive investigation of this group yet.

But I found a study, published 2002, where they compared collections from Oregon with three sequenses from Genbank. They formed three lineages. One with only the japanese sequense from Genbank, one with two separate collections from Oregon, and one with the rest of the Oregon collections, closer to the two other sequenses from Genbank (Norway and USA). Unfortunately, they didn’t tell what the different collections looked like.

Ok, nope not good enough…
By: Douglas Smith (douglas)
2010-02-25 23:49:49 PST (-0800)

But, I can’t use your gut. Nor can anyone else looking at these. That isn’t good enough. You need make a list of observable features, and then use your gut to see which of those features are significant, and then tell me what to look for, or not. I can’t really look at your gut to see what I should be calling a species. But I can look at available features and compared to descriptions listed in publications, and if I do that, these are T. flavovirens.

With yellow, I mean, yellow gills…

For some variation, if you click on the list for Stanford Campus there, there are two other photos taken of T. flavovirens from the same spot in past years. These are obs.:


(Which also show yellow gills…)

So, until you can tell me a feature that I can observe as different, and get it published, I claim I can id these as T. flavovirens. Or else I think the ave. of everyone’s gut will devolve most of the ids here to genus only…

I look at your and Walt’s photos, and my gut is telling me that they look a lot like all the same species… But I might not have that sensitive a gut.

I’m willing to believe that the western stuff is some other species, and that my id’s are just plain wrong, you just have to tell me what to look for. And if it is “Tricholoma sp.” give me an idea of what other species it might be?

It’s a gut feeling…
By: Noah Siegel (Noah)
2010-02-25 18:10:49 PST (-0800)

that’s tough to explain. they just look different_.

Irene probably says it a lot when we use European names on our collections…

I brought up T. aurantium earlier;
http://mushroomobserver.org/27840?search_seq=1332810 yours from Europe
http://www.swefungi.se/PAGES_PZ/Tricholoma_aurantium.html from Irene’s site
http://mushroomobserver.org/1987?search_seq=1332810 yours from CA
http://mushroomobserver.org/23887?search_seq=1332810 and mine from MA
Now, are all these the same species?

or Tricholoma portentosum
http://www.swefungi.se/swindex.html Irene’s from Sweden
http://mushroomobserver.org/5716?search_seq=1332816 yours from CA
http://mushroomobserver.org/13198?search_seq=1332816 the second picture they are frozen so it’s not a good example…

OK. It may be an Eastern difference.
By: walt sturgeon (Mycowalt)
2010-02-25 14:11:47 PST (-0800)

Our conifer T. flavovirens has yellow, no doubt about it yellow gills…

By: Douglas Smith (douglas)
2010-02-25 10:59:32 PST (-0800)

I’m still not sure what are the features that Walt and Noah are reacting to here, and seem to think this is a variation that isn’t normal for T. flavovirens. Is it the white stipe? (off-white?) Looking that photos I have for T. flavovirens from around the area, and specifically from the same spot, the stipe has a variation of colors from off-white, to yellow, to light tan. And smooth variations in between.

Tricholoma flavovirens var. albipes
By: Irene Andersson (irenea)
2010-02-25 09:31:49 PST (-0800)

is described by Peck from North America, this may be it.
I don’t know if it ought to be considered a species of its own. That could be worth an investigation.
It also seems to fit rather well with the description of a new species, so far known from the Baltic countries and Scandinavia: Tricholoma ulvinenii.

By: Douglas Smith (douglas)
2010-02-25 05:48:35 PST (-0800)

Still can’t quite see what you are reacting to here… Taking a look at obs. 13197 and 13855 for comparison, seems to have rather similar features. The yellow-green cap with tan-brown tones, esp. in the disc, the viscid cap, the even yellow gills, found under pines, the mostly off-white fibrous stipe…

I mean these aren’t the best examples or the best photo, but it is fairly consistent with other obs. What are the features that make this different, or makes for a different “western” to “eastern” form?

(I couldn’t find an obs. of this species by Walt for comparison… so I’ll just pick on yours.)

By: Noah Siegel (Noah)
2010-02-25 05:23:06 PST (-0800)

this is typical of what gets called flavovirens in CA… Just for fun look at the CA. collections of T. portentosum and T. aurantium

A reason why here?
By: Douglas Smith (douglas)
2010-02-24 23:02:28 PST (-0800)

Is there a reason why here you don’t think this is T. flavovirens? I’ve been finding these in the same spot for years, and they are pretty clearly T. flavovirens. (I’ve even eaten them, so there is that for diagostics…) They were found under pines, with a viscid cap, and the yellow gills. What are the possible choices to say that this is just some other Tricholoma?

Created: 2010-02-23 06:40:46 PST (-0800)
Last modified: 2018-11-08 14:18:20 PST (-0800)
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