Observation 158435: Marasmiellus volvatus Singer
When: 2014-01-01
No herbarium specimen

Proposed Names

62% (2)
Eye3 Eyes3
Recognized by sight: ID by D. Jean Lodge. Confirmed by Jadson Oliveira
Used references: Macrohongos de Costa Rica, Vol. 2, Milagro Mato, R. Halling, G. Mueller, Page 96
56% (1)
Recognized by sight

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Eye3 = Observer’s choice
Eyes3 = Current consensus

Comments

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Thank you, Amanitarita
By: Susanne Sourell (suse)
2016-12-02 11:52:07 PST (-0800)

Hi Debbie, many thanks for your motivating comments. I sincerely hope that my observations will be as useful to MO members as I take advantage of other posts. Indeed an immense amount of information about Neotropical Fungi has accumulated over the years. Definitely helping to shed light on fungi in the Neotropics.

Danny
By: Susanne Sourell (suse)
2016-12-02 11:29:43 PST (-0800)

Many thanks for bringing together all this information. I can’t figure out a solution either. But I definitely will have a very careful look if I encounter these white beauties again.

orbicular disc!
By: Danny Newman (myxomop)
2016-12-01 17:54:19 PST (-0800)

if Berkeley’s orbicular disc is this:

(taken from Observation 198339)

and this is both definitely a character of M. coilobasis and definitely not a shared character with M. cubensis, I think we can separate our white, “volvate” Marasmiellus spp. macroscopically like so:

1. Lamellae intervenose -————————————- 2
1. Lamellae not intervenose -—————————— M. volvatus

2. Stipe superficially affixed to substrate -——- M. cubensis
2. Stipe emerging from hollow orbicular disc -- M. coilobasis

Susanne
By: Danny Newman (myxomop)
2016-12-01 16:30:50 PST (-0800)

i see now that there are actually three “volvate” Marasmiellus species according to that paper, two of which are in section Candidi (_M. volvatus and _M. coliobasis) and one of which is in sect. Tricolores (M. cubensis), so all those Marasmiellus sect. Tricolores proposals are erroneous. Confusingly, The Macrofungus Flora of China’s Guangdong Province does not describe anything volval in its M. coilobasis description, nor is intervenosity mentioned regarding the lamellae. It also mentions some brown at the disc and and at the base of the stem, which ought to set it apart in Candidi key, but doesn’t. I do not have access to:

Singer, R. 1973. The genera Marasmiellus, Crepidotus, and Simocybe in the Neotropics. Beihefte zur Nova Hedwigia. 44:1-517

so I can’t see how well Singer’s original description matches that one. I did, however, manage to find Berkeley’s description in:

Berkeley, M.J. 1856. Decades of fungi. Decades LI – LIV. Rio Negro fungi. Hooker’s Journal of Botany and Kew Garden Miscellany. 8:129-144

which does mention intervenosity. Go figure.

So here is this third volvate species (M. coilobasis) to contend with, which may or may not be all white like the others. Assuming it is (as the Nivero paper makes no mention of cap or stem pigment), and assuming it’s intervenose, that character sets it apart nicely. The non-intervenose M. volvatus and M. cubensis still appear to differ only/primarily microscopically, aside from the volva location notion from Jean and Jadson, but the volva looks pretty low in the Niveiro figure, so how low is low enough? Do we trust Taylor Lockwood?

If so, those volvas (volvae?) look just as high up the stipe as those of anything being called M. volvatus. To make matters worse, no volva or volva-ish character is mentioned for M. cubensis in either

Dennis, R.W.G. 1951. Some Agaricaceae of Trinidad and Venezuela. Leucosporae: Part 1. Transactions of the British Mycological Society. 34(4):411-482

Berkeley, M.J.; Curtis, M.A. 1869. Fungi Cubenses (Hymenomycetes). Botanical Journal of the Linnean Society. 10:280-392

or Fungus Flora of Venezuela and Adjacent Countries

All three references do, however, say the lamellae of M. cubensis are “conspicuously intervenose” (a.k.a. interstitiis trabeculatis adnexis), which takes away M. coilobasis’ easy separation on the basis of that character! Can we then conclude that any all white, non-intervenose, volvate Marasmiellus is M. volvatus? How then to distinguish M. cubensis from M. coilobasis? Why is my nose bleeding? Is there a god?

such a pleasure
By: Debbie Viess (amanitarita)
2016-12-01 09:31:54 PST (-0800)

to see your continuing fine work here.
thanks for sharing with the MO community.

Marasmiellus volvatus
By: Susanne Sourell (suse)
2016-12-01 02:11:24 PST (-0800)

For more information on M. volvatus see here: Niverro et al. ‘Primer registro de Marasmiellus volvatus (Marasmiaceae: Agaricomycetes) en Argentina, una especie poco conocida
First record of Marasmiellus volvatus (Marasmiaceae: Agaricomycetes) in Argentina, a rarely known species’ ,
http://www.sciencedirect.com/...
I conclude that M. volvatus does not have intervenose lamellae, M. cubensis would have occasionally interveined lamellae according Pegler (Agaric Flora of the Lesser Antilles) . Danny, does the help in our discussion ‘how to differentiate between Marasmiellus cubensis and M. volvatus on macroscopic details’?

Created: 2014-01-23 11:48:22 PST (-0800)
Last modified: 2016-12-01 16:33:45 PST (-0800)
Viewed: 95 times, last viewed: 2016-12-02 15:11:29 PST (-0800)
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