Volvariella sp

[flaxton]

Has anyone any experience of Volvariella?

This was found today in soil with no sign of dead wood but as I wasn't really looking for it there is just a chance that there was some hidden below the surface.

As it was a small (2cm) white fruit-body the first choice was Volvariella pusilla but the pp was too big

the cheilocystidia was rostrate

This then took me to V caesiotincta and although the spores were a bit big at 8X4m

it was certainly a better fit.
Any suggestions?
Thanks
Mal

[Andy Overall]

Originally Posted by flaxton

Has anyone any experience of Volvariella?

This was found today in soil with no sign of dead wood but as I wasn't really looking for it there is just a chance that there was some hidden below the surface.

As it was a small (2cm) white fruit-body the first choice was Volvariella pusilla but the pp was too big

the cheilocystidia was rostrate

This then took me to V caesiotincta and although the spores were a bit big at 8X4m

it was certainly a better fit.
Any suggestions?
Thanks
Mal

I had V. caesiotincta from Hampstead Heath last year, fruiting from buried wood. I remember it having a distinct smell, can't remember the type of smell though. If you pop it into a container for a short while and then get your nose in, this should be evident. My specimen certainly resembled what you have in the picture. As I'm not at home whilst writing this, I can't refer to my micro details.

Andy

[mollisia]

Hello,

I would have said Volvariella pusilla, as was your first idea too. What means "the pp was too big"?

V. caesiotincta is very diferently coloured and smells like geranium. it also grows on very rottem wood of preferably Fagus. I found it yesterday here.

best regards,
Andreas

[flaxton]

Originally Posted by mollisia

Hello,

I would have said Volvariella pusilla, as was your first idea too. What means "the pp was too big"?

Andreas

Thanks Andreas
FOS says the hyphae in the pilepellis of V pusilla should be 4-10um thick not the 20um in my find. It also says the cheilocystidia with rostrum like projections is only found in V caesiotincta.

Mal

[mollisia]

Dear Mal,

in my german version of FOS, the rostrate cheilocystidia are only siad to be a diffenciating character compared to V. murinella, not that it is the only species with such cystidia. And what concerns the width of the pileipellis hyphae, the given measurements are only for the very collection that it is depicted. Like always in FOS, that means not necessarily that this is the complete range of the species. If you compare with other literature, e.g. Flora Neerlandica, you read: "Pileipellis a cutis, made up of cylindrical hyphae, c. 10-20 µm wide, with very pale incrusting pigment."
All authors are the same opinion, that V. caesitincta is a grey capped species with dark volva, growing on decayed wood, with caps of 3-6(8) cm diam.. V. pusilla is smaller, only up to 3(4) cm, white, has white volva and grows on the ground. All keys I tried (BFF, FAN, Funga Nordica) lead to V. pusilla for your collections, because of the white, silky (not hairy) caps and the non-pubescent stipe.
What concerns the rostrate cheilocystidia, you are correct that those are given as character for V. caesiotincta. But they should be not only rostrate, but often forked or branched, which I couldn't see in your foto. Be it as it is, I would not lay too much emphasis on the shape of the cystidia if this would be the only disagreement. So I would name it V. pusilla.

best regards,
Andreas

[flaxton]

Thanks for the explanation Andreas. Happy to log it as V pusilla.

Mal

[flaxton]

Sent this with the Omphalanoid fungi to Kew and this one came back as Volvariella hypopithys.

Mal