Boletus albidus?

[flaxton]

Originally Posted by Andy Overall

I don't think so Mal. I've found these immature, yellowish, erythropus myself where as they mature, become the normal brown colour. I can see from Monkeyd's previous shots that they start out yellow and then quickly take on the familiar brown appearance.

Interesting though Dave that the two species are associating with the same tree and that Russula are in on the act also. Just gives you a snippet of the competition that is going on between species there.

Andy

Andy

I have always been of the opinion (possibly wrongly) that the young bright yellow justified the var discolor tag whereas if it stayed pure yellow it was B junquilleus(pseudosulphureus)

Mal

[Andy Overall]

Thats a valid opinion as any Mal. However, in my opinion, when you get a handful of distinctly different colour variations within one species known as Russula graveolens I don't think that a yellow cap, for a short period of time, on one Bolete species warrants the tag 'var'. Unless this supposed var. is distinctly different in any other way, namely microscopic or DNA, isn't this just the same species??

Andy

[flaxton]

Originally Posted by Andy Overall

Thats a valid opinion as any Mal. However, in my opinion, when you get a handful of distinctly different colour variations within one species known as Russula graveolens I don't think that a yellow cap, for a short period of time, on one Bolete species warrants the tag 'var'. Unless this supposed var. is distinctly different in any other way, namely microscopic or DNA, isn't this just the same species??

Andy

Especially as the same colour variation in B luridus is given no standing at all

Mal

[Monkeyd]

Originally Posted by Andy Overall

Interesting though Dave that the two species are associating with the same tree and that Russula are in on the act also. Just gives you a snippet of the competition that is going on between species there.

Andy

Really enjoying getting out & stumbling upon all the Mycorrhizal species in evidence at this time.


Suprises me how many diffrent genus can be found in small area.

Here are Laccaria amethystea, Amanita fulva & Russula sp (possibly parazurea?) all within a meter or so of each other.
Interesting how they're not mixed in together but are in their own clumps.

Edges of there specific rhizo-zones or are the myceliums not able to inhabit the same areas?


I dunno

[fairplay]

Fungi are known to put out their own barriers - a good example is the 'Spalting' you see in Beech wood, usually caused by species of Xylaria.

The same probably applies with the Agarics as well to some degree.

[Andy Overall]

Originally Posted by flaxton

Especially as the same colour variation in B luridus is given no standing at all

Mal

Exactly Mal. Sometimes it really does come down to who you are talking to and who's work you care to follow. There have always been the splitters and the lumpers. In cases like this, one needs to draw upon one's own experience in the field and try back up it up with some hard evidence, not easy and very time consuming. I mentioned Russula graveolens, well its particularly rich in this species in areas of Hampstead Heath and the colour variation is phenomenal and easily different enough between them to appear to be different species. But according to 'some' of the experts in the genera this is one species. I also have trouble with the concept of Russula grisea & R. ionochlora which are also frequent in these parts, the difference between them, even at a microscopic level is quite minimal and quite frankly splitting hairs. Again it depends upon what you read and by whom, as the descriptions seems to flit between the two, from one publication to another. The Oil Slick description could quite easily blur into grisea as does the lilac/purple flesh beneath the cap cuticle, move between the two species. I know that Russula are renowned for being frought with difficulty but this doesn't help. I have taken a look at many different collections of what I think are 'supposedly' both species and find very little difference between them. Is one just a form of the other??? Have fun.

Cheers

Andy

[flaxton]

Andy

I still have no idea what justifies a "species" and what is only a "var". When as you say there is almost no microscopic differences and the macroscopic details merge and yet they are classed as two species and in other species different sizes or shapes of spores and other details only justifies a var

Mal

[Andy Overall]

Originally Posted by flaxton

Andy

I still have no idea what justifies a "species" and what is only a "var". When as you say there is almost no microscopic differences and the macroscopic details merge and yet they are classed as two species and in other species different sizes or shapes of spores and other details only justifies a var

Mal

Well, I know, but this is what you get. Obviously there are big differences between most species, macoscopically and microscopically and clearly different but some are far too close for comfort. That is all I can say really but it is genuinly what I have concluded from the species I mentioned.
I would like to take a Russla expert out into the field amongst both R. grisea and R. ionochlora and ask for him/her to show me which of the two he/she thinks is either and then to demonstrate it to me showing me the distintive microscopic differences. But that is probably never going to happen so I have to draw my own conclusions, drawing together my own knowledge and work that has been done by others. Thats all you can do. With most species I come across I don't have any problems with their treatment/concept but now and again, as with those I have mentioned, questions arise in my mind as to their validity.

Cheers

Andy