Gyroporus cyanescens
This is a Gyroporus, probably Gyroporus cyanescens. G cyanescens is a bolete with a hollow stem at the base, one of the distinguishing characteristics of this type of bolete. It is an epigeous ectomycorrhizal fungi. Like many Australian boletes, it stains blue, although the blue is quite different to the blue-green of many other boletes.
The blueing reaction is easily explained through biochemistry. A compound called variegatic acid remains colorless unless it is exposed to oxygen. The cell walls of Gyroporus cyanescens are easily broken, exposing the variegatic acid to the air. The oxygenase enzyme converts the variegatic acid to its quinone methide, which is blue. Interestingly, in many other boletes, in the absence of oxygen, variegatic acid is converted to variegatorubin, which is responsible to the red color found in many members of this group. The possible functions of the variegatic acid and its color shifts to blue or red are unknown.
The internet reports the fungi occurring in France and North America and it has been described in some books as Gyroporus variabilis. The specimen below was found in a bush park in suburban Sydney, Australia.
Gyroporus cyanescens is described by some non-Australian sites as a delicious edible mushroom, but as I'm unsure about this identification, I wouldn't try it.
| Gyroporus cyanescens | - Gyroporus cyanescens. Looks like a pale bolete, May, 2007, Coonan Street Walk, Lane Cove River National Park, Turramurr | |
