Green species of Russula

[Fungus Ken]

Anyone with any experience of trying to identify species of Russula will know how hard it can be, in particular because of the variability of the cap colours, even within a species. Green ones are no exception. Here, for example, is Scriber's recent photo of a dark green Russula:



If you were trying to identify this from Geoffrey Kibby's publication, The Genus Russula, you would quickly realise that there are actually upwards of 25 species that key out in his section headed "Green colours".

The common species with a green cap you might come across are the green form of Russula cyanoxantha - var peltereaui, Russula aeruginea and Russula heterophylla. All three of these tend to have pale to mid-green colours, unlike the specimen in the photo, and they can be quite tricky to separate.

Russula virescens is another, perhaps less common, green species. However, this can easily be distinguished by its scurfy, cracked cap surface (particulary towards the edge of the cap), brittle creamy gills and mint-green to grey-green colours. The specimen in the photo does not have any of these characteristic features.

So what is the specimen in the photo? That's a good question. It might just be Russula cyanoxantha, and rubbing iron salts on the stem and watching for any colour change would help in narrowing down the options. In R. cyanoxantha the colour change would be nil to slightly greenish.

But I would hesitate to try to put a name to any Russula without a good deal more information. To use Geoffrey Kibby's key you need all of the following macroscopic characters (and some microscopic ones too, usually):

- cap colour
- how far the cap cuticle peels from the edge
- whether the stem is white or is flushed with any colour
- cap size
- spore colour
- taste of flesh (acrid/hot, mild, bitter)
- whether the flesh discolours when cut or bruised

If you do your homework carefully, it is possible to find an answer for your mystery Russula, but it is all too easy to fall into the trap of assigning a name because it looks a bit like the picture in your book. You just can't rely on this method for separating the different species of Russula.

Ken

[Leif]

And associate organism, season, and smell of course. There are also chemical tests too as I am sure you know.

The Russula genus is a mine field. I can reliably identify some, but not many.

[Fungus Ken]

Originally Posted by Leif

And associate organism, season, and smell of course. There are also chemical tests too as I am sure you know.

Yes, the list of possible checks is a lengthy one but with Russulas you need every bit of assistance you can get.

Originally Posted by Leif

The Russula genus is a mine field. I can reliably identify some, but not many.

I find with Geoffrey Kibby's book, which includes a synoptic key, that I can now put names to more of the Russulas I find...

... but that's not quite the same thing as reliably identifying them.

Ken

[flaxton]

Although not the best picture


Shows the much paler cap of virescens and the scaly cracked cap surface.

Mal

Ps
I can recommend the new Kibby book it describes in detail all the UK species plus others that may be found in the future.

I used it to id anthracina new to Yorkshire

[FungiJohn]

Nice one Mal. I always think 'Geoff' when Russula's are mentioned ... nibble, smell, habitat, what tree

[NickCantle]

I always think 'Ken'

[Fungus Ken]

Originally Posted by flaxton

Shows the much paler cap of virescens and the scaly cracked cap surface.

I'm jealous again. I've never found this myself, although I have been on forays where it was found.

Originally Posted by flaxton

I can recommend the new Kibby book it describes in detail all the UK species plus others that may be found in the future.

I used it to id anthracina new to Yorkshire

The blackening Russulas have been confused in the literature, which means a lot of the earlier records are unreliable. Hopefully things should be more straightforward now with Geoffrey Kibby's publication.

Ken

[Fungus Ken]

Originally Posted by NickCantle

I always think 'Ken'

That's only because you've never been on a foray with Geoffrey Kibby. He is "the man", in this country at least, when it comes to Russulas.

Ken

[NickCantle]

Ken, I'm relying on you to introduce me to Kibby and Henrici

[cybershot]

I've never really been convinced about my ID of this apple green species which I found in 2006 and named Russula heterophylla :