Observation 159625: Bolbitius Fr.
When: 2014-02-12

Notes: These were growing on woody debris from an old oak.
Caps up to 3.1 cm across.
Stipes up to 6.5 cm long and 0.40 cm wide, hollow and very fragile.
Spore print was a light reddish brown. Spores not amyloid.
Spores ~ 9.1-11.0 X 5.8-6.9 microns, ellipsoid to elongate and smooth. Q(ave) = 1.66.
Did not see any Pleurocystidia. There was some scattered cheilocystidia that was ~ 35-37 X 7-8 microns, subcapitate.
Fruit-bodies were delicate and fragile, especially the stems.
Pluteus sp seems reasonable but even then, the spore color isn’t quite right.

Proposed Names

-23% (2)
Recognized by sight
59% (6)
Recognized by sight
-9% (5)
Recognized by sight
Used references: Good call Walt. Fits the description in Mushrooms Demystified and the spores do have a faint germ pore.
-8% (4)
Recognized by sight: Yellowish pileus and stipe.
Used references: FAN6
Based on microscopic features: Large spores
-19% (3)
Recognized by sight
Based on microscopic features

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

Eye3 = Observer’s choice
Eyes3 = Current consensus


Add Comment
By: Byrain
2014-02-15 21:29:04 CST (-0500)

FAN6 also has them as synonyms.

“5. Bolbitius reticulatus (Pers. :Fr.) Rick., Blätterpilze 1: 68. 1915. –
Fig. 132.
Agaricus reticulatus Pers., Syn. meth. Fung.: 341. 1801; Agaricus
reticulatus Pers. :Fr., Syst. mycol. 1: 238. 1821; Pluteolus reticulatus
(Pers. :Fr.) Gillet, Champ. France: pl. 373. 1878; Pluteolus aleuriatus
var. reticulatus (Pers. :Fr.) J. Lange in Dansk bot. Ark. 9(6): 49. 1938.
– Agaricus aleuriatus Fr., Observ. mycol. 1: 49. 1815; Agaricus aleu-
riatus Fr. :Fr., Syst. mycol. 1: 238. 1821; Pluteolus aleuriatus (Fr. :Fr.)
P. Karst., Ryssl., Finl. Skand. Halföns Hattsvamp.: 428. 1879; Bolbitius
aleuriatus (Fr. :Fr.) Sing. in Lilloa 22: 490. (1949) 1951; Bolbitius
reticulatus var. aleuriatus (Fr. :Fr.) M. Bon in Doc. mycol. 20(78): 39.
1990; Bolbitius reticulatus f. aleuriatus (Fr. :Fr.) Enderle in Ulmer
Pilzfl. 4: 50. 1996; Bolbitius pluteoides Mos. in Fung. rar. Ic. col. 7:
27. 1978.”

By: walt sturgeon (Mycowalt)
2014-02-15 19:40:11 CST (-0500)

Current Name:
Bolbitius reticulatus (Pers.) Ricken, Die Blätterpilze 1: 68 (1915)

Agaricus aleuriatus Fr., Observ. mycol. (Havniae) 1: 49 (1815)
Agaricus reticulatus Pers., Icon. Desc. Fung. Min. Cognit. (Leipzig) 1: 13 (1798)
Agaricus reticulatus ß aureus Alb. & Schwein.
Bolbitius aleuriatus (Fr.) Singer, Lilloa 22: 490 (1951) 1949
Bolbitius reticulatus f. aleuriatus (Fr.) Enderle, Ulmer Pilzflora 4: 50 (1996)
Bolbitius reticulatus (Pers.) Ricken, Die Blätterpilze 1: 68 (1915) f. reticulatus
Bolbitius reticulatus var. aleuriatus (Fr.) Bon, Docums Mycol. 20(no. 78): 39 (1990)
Bolbitius reticulatus var. australis (E. Horak) Garrido, Biblthca Mycol. 99: 27 (1985)
Bolbitius reticulatus (Pers.) Ricken, Die Blätterpilze 1: 68 (1915) var. reticulatus

Not reticulatus
By: Irene Andersson (irenea)
2014-02-15 13:36:47 CST (-0500)

because there’s no sign of reticulation on the cap, and the yellow coloured stem is not a reticulatus character. The same goes for aleuriatus…

any comments…
By: Richard and Danielle Kneal (bloodworm)
2014-02-15 11:33:16 CST (-0500)

as to why this isn’t Bolbitius reticulatus (Persoon) would be very much appreciated.

By: Richard and Danielle Kneal (bloodworm)
2014-02-15 09:41:11 CST (-0500)

any chance this can get sequenced?

Thanks to…
By: Byrain
2014-02-15 00:59:07 CST (-0500)

Christian’s obs 159708, my thoughts on this changed a little. I think for Ron’s observation the choices are limited to B. titubans or the same thing as Christian’s obs which is not B. reticulatus/aleuriatus or B. titubans. The spores & spore wall are too thick & the stem is too yellow to match the European reticulatus/aleuriatus concept & at least in Christian’s observations the colors are don’t seem right for B. titubans. Since both reticulatus & aleuriatus are European names I think we should come up with our own. Now we need someone to scope the white stemmed B. reticulatus in CA and see how that matches up.

Well, I do have the dried specimens
By: Ron Pastorino (Ronpast)
2014-02-14 18:11:56 CST (-0500)

if anybody ever saves enough change in their Bolbitius Biggy Bank for a DNA test.

With regard to the lilac tints on the caps, on my computer, if I go to maximum size on both my photos, the lilac tints are clear, especially on the outer portions of all the caps, including the one with the faint yellowish disc as well as the smaller crumpled one.

I agree with Christian and Noah that these are not B. titubans. I think they are are what we have locally been calling B. reticulatus/B. aleuriatus. The yellowish stipes may be a result of different host influences. Whether there is enough differences to merit a new species name will have to wait for someone to do a thorough study with DNA analyses.

However, I don’t really see the point of sliding everything into a big genus buckets that makes it difficult for users to find anything that already has a history of common or local usage.

By: Byrain
2014-02-14 13:21:14 CST (-0500)

I might be able to spare a few dollars for DNA work if I just knew who to ask/trust. Last person who said yes lost most of the specimens instead…

And yea, this one is hard to pin down. It would be good to do the DNA work on the more clear cut yellow stemmed B. reticulatus too if anyone saved any of those. And also the white stemmed one that actually looks like the European concept.

so much variability…
By: Debbie Viess (amanitarita)
2014-02-14 13:14:26 CST (-0500)

and such flexible fruiting styles. hard to pin this one down.

Noah’s photo comparison does not show the same colors as your original photo, Ron…his shows a good bit more purplish; he did indeed adjust the photo: for “glare,” but it changed the color, too. I do not see that reddish tint in your photo. plus, the yellow in the cap of that second photo has nothing in common with B. reticulata.

Round and round we go. If only someone had funding to run DNA, we could solve this once and for all!

My “friends and family discount” is rather limited in numbers allowed, and I need to save it for special cases, not battles of the titans.

How bout you fellas? Got some DNA monies to burn? If so, throw a little bit towards the lodgepole Hygrophorus speciosus too, since despite the fact that it is exactly the same morphologically with other western examples of the species (and quite a few eastern ones, too), and pine is listed as an alternate habitat in many sp. descriptions of specious (but NOT the original description by Peck in 1895, too true), prove to us that your beliefs are reality based. It’s gonna take DNA at this point.

By: Byrain
2014-02-14 12:35:04 CST (-0500)

The current European concepts consist of variable spore ranges and colors, I’m not convinced that this is B. titubans, that this is not B. reticulatus, or that B. reticulatus sensu CA with the yellow stem is the same thing as the European species, but since you have specimens its possible these questions could still be answered. I don’t have any more points to add now and will be interested even if I am eventually proven wrong. :)

Still, my question remains, who wants to do DNA on Bolbitius collections? I unfortunately neither have the skill or equipment to volunteer.

Christian, that is not my voting style at all…its frankly insulting that you think it is. And its disappointing that you no longer care about this interesting discussion, I am fully capable of being convinced if you actually try, are you capable of being convinced too? I only try to use “I’d call it that” with European names when I am certain that its either that species or that its fits the European concept really well (At least on paper) and “As if” only when the suggestion is wrong to the point its not even being worth considered (Which at this point will never be true with either suggestion). In the event someone lays forth a convincing argument that the species are actually different my votes will change. See obs 158931 for an example.

Thanks Rocky,
By: Ron Pastorino (Ronpast)
2014-02-14 10:13:11 CST (-0500)

and yes, I do have specimens.

By: Rocky Houghtby
2014-02-14 09:01:41 CST (-0500)

Micrographs, Ron. I’m sorry if I missed it below, do you still have specimens?

If anybody is still there here are
By: Ron Pastorino (Ronpast)
2014-02-13 22:57:32 CST (-0500)

a few more counterpoints…
Several of the descriptions provided by Byrain use the words “violaceous”,lilac gray",and “brownish violet” to describe some of the colors seen on the caps of B. reticulatus. That is clearly seen in the cap of the first photo that Noah enlarged. I have never seen even a hint of that color in any B. tibutans.
Spores: Lot of ambiguity here. But see my MO#119013 where I measured the spores of a collection of B. tibutans. They were; 11.5-13.9 X 6.1-8.1 microns. Fairly distinct from 9.1-11.0 X 5.8-6.9 microns using the same equipment. Also, the former seemed to have thicker walls if that means anything.
Defense rests….

By: Christian (Christian Schwarz)
2014-02-13 22:40:17 CST (-0500)

I changed my voting style on this one to line up with yours (on account of this being a special occasion, and because the difference and diversity of opinions is what makes this website useful and err… um… vaulable or something).

More accurately – because I have no doubts that this is not B. titubans (and is _B. aleuriatus sensu CA).

I laid out all my arguments below. You aren’t convinced, I no longer care.

References used
By: Byrain
2014-02-13 20:54:40 CST (-0500)

For B. reticulatus.



Henderson, D.M., Orton, P.D. & Watling, R. (1969). British Fungus Flora: Agarics and Boleti: Introduction. HMSO: Edinburgh, Scotland. 58 p.
Noordeloos, M.E., Kuyper, T.W. & Vellinga, E.C. (2005). Flora Agaricina Neerlandica—Critical monographs on the families of agarics and boleti occurring in the Netherlands. Volume 6. Coprinaceae & Bolbitiaceae. Taylor & Francis: Boca Raton, FL. 227 p.

Both European,

Mushroom expert:

REFERENCES: (Persoon, 1798) Ricken, 1915. (Fries, 1821; Saccardo, 1887; Kauffman, 1918; Arora, 1986; Hansen & Knudsen, 1992; McNeil, 2006; Miller & Miller, 2006.)

I’m not familiar with all of them, but at least a handful are European.

So, European literature is no good because it doesn’t “encompass the variability we see in California mushrooms” while Californian literature based off the same European literature does? Christian, it seems you’re voting “I’d call it that” on a sensu CA name after saying, “And I try to only vote I’d Call It That when I think it’s actually described and not just a sensu North America or sensu California name.”

Spore sizes
By: Byrain
2014-02-13 20:24:46 CST (-0500)


Spores 10-16 × 6-9 µ (Mushroom expert)
Spores 10-14 × 6-9 µm (Mykoweb)
Spores (8.5)9.5–15.0(15.5) × 6.0–9.0 × 5.5–8.0 μm, av. 10.4–12.6 × 6.7–7.9 × 6.5–7.3 μm (var. titubans, FAN6)
Spores 10.5–14.0(15.0) × 6.5–8.5(9.0) × 6.0–7.5 μm, av. 11.0–12.3 × 6.8–7.5 × 6.5–7.0 μm (var. olivaceus, FAN6)

B. reticulatus

Spores 9-13 × 4-6 µ (Mushroom expert)
Spores 8.5-11.0 × 4.5-6 µm (mykoweb)
8-12 × 4-6μ (Mushroom hobby)
Spores (6.5)7.0–12.0(12.5) × (3.5)4.0–5.5(6.5) μm, av. (7.9)8.4–9.9 × (4.1)4.5–5.2 μm (var. reticulatus, FAN6)
Spores 7.0–11.0(11.5) × 4.0–5.5(6.5) μm, av. 8.3–9.5 × 4.5–5.2 μm (var. pluteoides, FAN6)

Ron’s observation

Spores ~ 9.1-11.0 X 5.8-6.9 microns

Now the FAN6 discussion.

B. titubans

“Bolbitius titubans var. titubans is easily recognised by the bright yellow
viscid pileus and the fragile, deliquescent nature of the basidiocarps
with free, orange-brown lamellae. It is better known under the name
Bolbitius vitellinus. Both names Agaricus titubans and A. vitellinus
were sanctioned by Fries but the former name has priority since it is
based on the oldest name, viz. Agaricus titubans Bull. 1789.
Some authors distinguish two or three taxa (species, subspecies, or
varieties) within this species. Bolbitius titubans sensu stricto is said to
be characterised by small basidiocarps with strongly striate, bright
yellow pileus and yellow stipe. Bolbitius fragilis is said to differ in the
paler yellow pileus and nonstriate pileus; B. vitellinus in the larger
basidiocarps and white stipe (e.g. Bon in Doc. mycol. 21 (84): 61.
1992; Watling in Br. Fung. Fl. 3. 1982). Occasionally also subtle dif-
ferences in spore size are reported. These differences could not be
established in collections from the Netherlands. All characters are com-
pletely intergrading. Therefore, B. fragilis and B. vitellinus are regarded
as phenotypic variants of B. titubans without taxonomic relevance. As
in many other coprophytic species, the size and stature of basidiocarps
is quite variable and dependent on size and quality of the substrate (see
Arnolds in Persoonia 18: 204. 2003). For an extensive discussion of
this subject, see Enderle et al. in Mittbl. Arbeitsgem. Pilzk. Niederrhein
3: 17–21. 1985).”

B. reticulatus

“Bolbitius reticulatus is easily recognised by the delicate basidiocarps
with a viscid, greyish, violaceous or brownish pileus and free, orange-
brown lamellae. However, size, colours, and structure of pileus surface
are exceedingly variable and have led to the distinction of several
species or intraspecific taxa. The typical, although rare, variant has
relatively large basidiocarps with a dark, wrinkled-rugulose pileus and
is described here as f. reticulatus. The most widespread variant with
medium-sized basidiocarps and a smooth pileus is occasionally distin-
guished as B. aleuriatus (e.g., Courtecuisse & Duhem, Guide Champ.
Fr. Eur.: pl. 1310, 1311. 1994). It is described here as f. aleuriatus.
Variants with small basidiocarps and a pale, smooth pileus were
described as Bolbitius pluteoides Moser (in Fung. rar. Ic. col. 7: 27.
1978). They are regarded in this Flora as a variety of B. reticulatus.”

As a side note, B. reticulatus is not described with a yellow stipe, how do we know this yellow stemmed variety is the same thing as the European species? The same European literature was used to identify it in the first place, but suddenly this literature is no good for B. titubans? Lastly, I find it amusing that Christian felt the need to change his vote to “As if” after failing to counter any arguments…

Nice discussion but I’m still in the B. reticulatus camp.
By: Ron Pastorino (Ronpast)
2014-02-13 17:49:46 CST (-0500)

These were definitely growing in the woods on an old decaying live oak log.
The faint yellow on the one cap is not a strong character for me.
I have seen a lot of B. titubans and these did not look like them.
There was no yellow in the caps of younger specimens and the hint of lilac of the fruitbody in it’s prime that Noah highlighted is noted in some of the descriptions for B. reticulatus.
In addition, the spore size of these is much closer to that of B. reticulatus than B. tibubans(Mushroom Expert has some spore photos of the later.)
Also, the little fruitbody in the photos did not show any yellow on the cap and was not oval or conical as is usually the case with B. titubans when young.
Ergo, my vote would still lean more heavily toward B reticulatus.

By: Byrain
2014-02-13 17:06:41 CST (-0500)

Noah, good point, but its overlooking the fact that one cap is mature & the other not so much.

Christian yea, I guess we do vote a bit differently, but I see nothing wrong with that. Its the diversity of opinions & perspectives that makes MO so great. Besides, MO votes are not set in stone like some old herbarium label.

I have a lot of Bolbitius collections, do you know anyone that would want to do DNA on them? How about Pholiotina & Conocybe? I’ve been even having trouble even getting Douglas to bite with my two recent Galerina collections even though I specifically messaged him… obs 158808 & obs 158594

By: Christian (Christian Schwarz)
2014-02-13 16:52:30 CST (-0500)

I agree with you that we need to collect more/describe more.
And no, I can’t point you to a better Bolbitius key. There isn’t one.

I use promising as a vote of confidence. And I try to only vote I’d Call It That when I think it’s actually described and not just a sensu North America or sensu California name.

So I guess we just vote really differently.

ah, that old sighting!
By: Debbie Viess (amanitarita)
2014-02-13 16:52:29 CST (-0500)

ironically, a Bolbitius reticulata with a WHITE stipe! That one faded to a whitish cap with just a hint of brown in the center.

I was primarily referring to the cap here in the thumbnail…which is purely brown, not gray.

One might construe gray alongside the yellow of the hidden cap, but yellow is the color that caught my eye, again, indicating titubans.

Guess that there are quite a few ambiguities in this obsie.

By: Noah Siegel (Noah)
2014-02-13 16:47:45 CST (-0500)

Top cap is Ron’s, with it darkened slightly to reduce glare, doing nothing to change color, lower photo is OB# 19517…

By: Byrain
2014-02-13 16:45:55 CST (-0500)

Yea, but can you point out a better north american Bolbitius key? I would LOVE to see it, we have to start somewhere. If you really want a good name for these, we need to start collecting, scoping & saving numerous collections then find someone willing & capable of doing the DNA work on all of them. I think until this is done, B. titubans which is described as even occurring in North America as the European key states is our best bet. Lots of work needs to be done, “Promising” is not a vote of confidence and several of my “I’d call it that” votes indicate that I think there its not possible to come up with a better name at the time (See my B. lacteus observation for an example). I also think some of these Bolbitius could easily be on several continents.

I understand that the key
By: Christian (Christian Schwarz)
2014-02-13 16:35:23 CST (-0500)

will rule things out.

But why are you so confident that the key is an accurate reflection
of reality?

If I understand it correctly, you’re using FN? That’s a European key.
There is no reason their descriptions should encompass the variability we
see in California mushrooms!

And even if it was a California-based key, remember that mycologists have
a long history of writing terrible keys. Try matching Largent’s Entolomas
to what you see in the woods. There are some major disconnects. Lack of broad
geographic experience, few collections examined, etc…

I started with keys, learned what I could. But at some point, you start to doubt existing understanding of certain groups, and start to take your own field experience more seriously than what any book might tell you.

Debbie – it’s pretty unbelievable to me that you can’t see the gray here.
But maybe I shouldn’t be so disbelieving. The color of Bolbitius caps can be hard to construe correctly sometimes:
observation 19517

you keep referring to your gray capped material….
By: Debbie Viess (amanitarita)
2014-02-13 16:32:50 CST (-0500)

but THIS sighting is brown and yellow.

there ARE NO young caps to compare, here.

yes, i know the definition of preponderance, thanks.

I do believe that what you collected in Santa Cruz is is a different species; this one sure resembles titubans, to my eye.

But I’ll just let you and Byrain hash it out.

Have fun!

By: Byrain
2014-02-13 16:27:02 CST (-0500)

Have you read the descriptions or tried the key? If the pileus has yellowish colors, we get sent straight to B. titubans. The spore sizes (Especially width) and width of the spore wall agree. They can be both greyish/brown, but I’m hard pressed to find any mention of yellow in the description for B. reticulatus, can we at least both agree that the 2nd image shows a cap with a yellow apex? And no, I haven’t found B. reticulatus yet, only read about it and viewed numerous images, I have seen what I think is probably B. titubans in the woods though, on dung and grassy places.

Edit: Just felt I should add that even though the key is pretty good, its no where near perfect for CA (Except for covering both suggested names). Here is an example where the key helped a lot.


Here is where it didn’t…


By: Christian (Christian Schwarz)
2014-02-13 16:19:36 CST (-0500)

means: “the quality or fact of being greater in number, quantity, or importance.”

I don’t think there’s anywhere near a majority of evidence for this being B. titubans.


The gray-capped ones start rather gray and sometimes have yellow in them. B. titubans (as shown in the description below) starts VERY yellow, often remaining so, and gets grayer as the caps age.

The gray-capped species are much less ovoid-cylindrical to broadly conic when young, like the B. titubans we see in ruderal habitats.

I’m honestly surprised that people are having this difficulty… I know you spend a lot of time in urban habitats, Byrain, but have you not seen the gray-capped Bolbitius in the woods? It looks like you only have urban observations of Bolbitius on MO. They’re really different…

The colors are variable
By: Byrain
2014-02-13 16:08:39 CST (-0500)

Here is the B. titubans pileus description.

“Pileus (10)15–65 mm broad, ovoid to ellipsoid at first, then conico-
convex, soon plano-convex to applanate, often with small obtuse umbo,
finally often with depressed centre, rapidly deliquescent, not hygroph-
anous, entirely lemon-yellow, golden-yellow to egg-yellow (K. & W.
2A5–7; 3A6–8, 4A7) at first, occasionally at centre orange-yellow, then
broad marginal zone becoming ochraceous, beige, flesh-coloured
brown or greyish brown, retaining bright yellow colour at centre, first
translucently striate at margin, radially sulcate-striate when mature,
smooth or in large basidiocarps occasionally rugulose or reticulate
around centre, surface viscid to glutinous when moist.”

Here is B. reticulatus.

“Pileus 12–30 mm broad in f. aleuriatus, 25–45 mm in f. reticulatus,
hemispherical to convex, then plano-convex to flattened, occasionally
with small umbo, not hygrophanous, quite variable in colour, at centre
violaceous black, brownish violet, grey-brown, olivaceous brown, dark
brown, dark grey, lilac-grey (e.g., K. & W. 5E5–7, 6D5, E6, 7F6, 8E7),
to the margin paler vinaceous or violaceous grey, pale grey, pale grey-
brown (e.g., 5D4–5, C2–4, 6C3, D4, 7C3), minutely sulcate-striate up
to halfway the radius or more, viscid when moist, smooth or slightly
rugulose (f. aleuriatus) to strongly wrinkled at centre (f. reticulatus).”

I think the important part is the pileus apex, dark brown like Christian’s observation vs. yellow like here. Here is the key:

“1. Pileus yellow or olive-yellow, occasionally olive-brown, becoming brownish with age; spores 9.5–15.0 × 6.0–9.0 ×
5.5–8.0 μm, rather thick-walled (0.5–1.0 μm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. B. titubans
1. Pileus without bright yellow colours but whitish, pinkish, greyish or brownish, occasionally with weak olivaceous
tone but then spores smaller: 7.0–11.0 × 3.5–5.5 μm and thin-walled
2. Pileus 30–70 mm, pale pink, pale orangeish to flesh-coloured at first, gradually fading to brownish; spores
11.5–16.0(16.5) × 8.0–11.0 × 6.5–9.5 μm, flattened, on the average over 13.0 μm long; growing on dung
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. B. coprophilus
2. Pileus usually with whitish, brown, grey or violaceous colours, occasionally pinkish but then smaller than 30 mm;
spores 7.0–13.0 × 4.0–7.5 μm, not flattened, on the average less than 12.0 μm long; on soil, plant remains or
wood, rarely on dung
3. Pileus whitish, cream-coloured or pale pinkish and small, up to 17(20) mm broad
4. Spores (10.0)10.5–13.0(14.0) × (5.5)6.0–7.5 μm, av. 11.5–12.0 × 6.6–7.0 μm; growing on soil or plant
remains in grasslands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. B. lacteus
4. Spores 7.0–11.0(11.5) × 4.0–5.5(6.5) μm, av. 8.3–9.5 × 4.5–5.2 μm; usually on decayed wood, occasionally
on soil, in forests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5b. B. reticulatus var. pluteoides
3. Pileus pale to dark grey, brownish or violaceous and usually larger, 12–45(70) mm broad
5. Pileus 30–70 mm broad; stipe 50–100 × 3–5 mm; spores (9.5)10.5–13.0 × (5.5)6.5–7.0(7.5) μm, on the
average larger than 11.1 × 6.5 μm; on soil or plant remains, recorded from glasshouses. . . 4. B. demangei
5. Pileus 12–45 mm broad; stipe 17–55 × 1–3(4) mm; spores (6.5)7.0–12.0(12.5) × (3.5)4.0–5.5(6.5) μm, on
the average less than 10.0 × 5.2 μm; usually on wood, rarely on soil in forests.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5a. B. reticulatus var. reticulatus”

The colors, spore sizes and possibly the relatively thick spore wall all point to B. titubans.

Edit: Christian says, “And no, there is not a preponderance of evidence on the titubans side.”, I hope he takes that back as he is most certainly wrong. :)
Still, I’m not convinced this is B. titubans either, but there are plenty of reasons why to think its promising.

jeez buddy…
By: Debbie Viess (amanitarita)
2014-02-13 15:57:37 CST (-0500)

at least come up with your OWN lines!!! ;)

we apparently still need a LOT more rain around here…

There are multiple licks of gray in these caps
By: Christian (Christian Schwarz)
2014-02-13 15:45:41 CST (-0500)

but just in case, I’d like to hear whether other people are having the same apparent hallucination as me.

What is the use of talking about viscidity here? Put it explicitly. I’m interested in knowing.

And no, there is not a preponderance of evidence on the titubans side.
Wishing doesn’t make it so.

other than perfectly describing all of these sightings of Bolbitius…
By: Debbie Viess (amanitarita)
2014-02-13 15:30:56 CST (-0500)

indeed, sliminess on their caps is wholly irrelevant to this conversation. WHAT was I thinking??!

This ID is still in dispute, but there is no gray in THESE caps, although that is not true for your Santa Cruz sightings, which probably ARE a different sp.

Wishing it doesn’t make it so, if the actual photos belie your words.

Wood is a possible (although unusual) habitat for titubans, as well. And stipe color varies from white to yellow, in both species. This one doesn’t have a lick of gray in its cap, though, just titubans brown and a remaining lick of yellow.

Plus, perhaps you have noticed that in this drought year, mushrooms are flocking to water reservoirs like downed logs, fruiting on, under or nearby. With a flexible habitat requirement, why not fruit outta well rotted and more importantly WET wood?

And again, in a drought, shaded areas (like woodlands) are better than exposed ones (like lawns). So if you can fruit in different places, this would be the year to extend yourself into some less commonly utilized habitats.

Spore print for Bolbitius titubans is described as “rusty brown,” but even some of the rusty brown spored corts can show a hint of red in their spore drop.

I would say the preponderance of evidence is on the titubans side.

Dang, where’s our tricorders? We could use an impartial referee, indisputable evidence, if such exists anywhere…

There is plenty of gray in these…
By: Christian (Christian Schwarz)
2014-02-13 14:59:52 CST (-0500)

and yes, brownish too.

I think these are pretty clearly the same as the gray-capped one I linked to (which sometimes has yellow in the cap as well, as shown by the images in that same observation).

That taxon has gone by B. aleuriatus from MD.

“All with brilliant yellow viscid caps, just like this obsie (the viscid part, at least)”

Doesn’t really mean anything since ALL Bolbitius are viscid-capped…

It’s possible that they are all B. titubans, but for now I’d consider them separate due to consistent and correlated morphological/ecological characters.

And the Orange County ones in that link really look very little like these in color…

here’s another brownish (not gray) capped titubans…
By: Debbie Viess (amanitarita)
2014-02-13 14:47:40 CST (-0500)

with a yellow, not white stipe, in grass habitat.


By: Debbie Viess (amanitarita)
2014-02-13 14:40:39 CST (-0500)

these don’t HAVE a gray cap, but a brown one. Same brown color that the yellow titubans becomes with age.

the gray capped species probably are something else.

your description of titubans habitat, Byrain, is completely in line with my observations: sometimes grass, sometimes dung, sometimes well-rotted wood or wood chips. All with brilliant yellow viscid caps, just like this obsie (the viscid part, at least); the yellow is almost gone here, but not quite.

were these along a path or in undisturbed forest?

Gray-capped ‘wild’ Bolbitius
By: Christian (Christian Schwarz)
2014-02-13 14:26:47 CST (-0500)

Whereas B. titubans – the yellow-capped slimy one often
grows in grass (and also on woodchips), it’s almost always in disturbed/urban areas.

This gray-capped one grows on wood more or less exclusively (although sometimes very decayed), and is found in ‘natural’ (less disturbed or ruderal habits).

Here’s a recent observation of mine: observation 153969 from Santa Cruz.

Arora calls it B. aleuriatus (although that’s a European name) in MD and notes the variability in whiteness/yellowness of the stipe in different collections in our area.

As far as the yellow colors or spore sizes ‘ruling out’ any European species, I’d assume the discrepancy is due to our material actually differing from those that the European descriptions are based on.

Does FN mention the gray cap being within the morpho range for B. titubans?

B. titubans has a variable habitat range
By: Byrain
2014-02-13 14:20:47 CST (-0500)

From FAN6:

HABITAT & DISTR. — Saprotrophic, solitary or subgregarious, occa-
sionally subfasciculate, on excrements of mammals, dung heaps, straw,
rotting hay and grass, piles of sawdust and on wood-chips mixed with
fertile soil, in grasslands, ruderal sites, gardens, parks, greenhouses,
rarely in forests, on all kinds of soil rich in nutrients. Widespread and
common in the Netherlands. April–Nov. Widespread in Europe, also
recorded from Asia, North Africa, and North America.”

I’m a bit pressed for time, I’ll add more later.

just for the record….
By: Debbie Viess (amanitarita)
2014-02-13 14:10:15 CST (-0500)

the brilliantly yellow B. titubans that I just posted on MO was also growing in wood chips, not grass. Maybe they are expanding their hosts?

It’s all the rage in our rapidly changing times.

there appears to be some variability in stipe color…
By: Debbie Viess (amanitarita)
2014-02-13 13:57:06 CST (-0500)

but descriptions for vittelinus/titubans include both white and yellow stipes.

as to the odd wood habitat for titans…it has happened before:


I also see yellow remnants on the cap of your second photo. the color shown on the rest of these faded specimens is not the gray-brown typical of reticulatus.

Bolbitius reticulatus
By: Byrain
2014-02-13 13:45:08 CST (-0500)

Has a dark brown cap disc, not a yellow disc clearly seen in your 2nd image, you’re right that mykoweb shows a yellow stem with is photos which his interesting.

Also see here – http://mushroomhobby.com/...

I think the cap colors are supposed to be more important than the stem colors. I’ll send you FAN6 later, the server its on is currently down… Its the best source I know for Bolbitius, but still only contains 5 species while we seem to have some species that do not occur in Europe.

I don’t have Flora Agaricina but
By: Ron Pastorino (Ronpast)
2014-02-13 13:28:54 CST (-0500)

from other sources(MykoWeb) I see that B. aleuriatus/reticulatus still looks reasonable.
The caps on these do not really show yellow(see the crumpled one that was growing protected under a taller fruitbody) and the pale yellow on the stipes seems to also be a characteristic of B. aleuriatus.
Also the spore size fits more closely to B. reticulatus than B. titubans, which appear to be much larger.
Then there is the habitat. B. reticulatus apparently is usually found on old rotting wood while the B. titubans favors grass and dung.

By: Byrain
2014-02-13 12:49:51 CST (-0500)

Specifically points out that Mushrooms Demystified is not a good source for lbms, why some still insist on using it for such, I’m not sure. According to Flora Agaricina Neerlandica vol 6, Bolbitius aleuriatus = B. reticulatus and the spores seem a bit big for that, not to mention the yellowish colors should rule it out immediately. As far as I am aware, all Bolbitius have a differentiated germ pore, some Conocybe & Pholiotina don’t, so maybe there are Bolbitius that lack it too? How thick is the spore wall?

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