Cap depressed to funnel-shaped, velvety or tomentose, later smooth, cap margin inrolled and remaining so for a long time. Gills forking. Spore print rusty, brownish or vinaceous.
At least eight species are described in Europe. With exception of Paxillus rubicundulus, that is relatively easy to recognize, the rest of the species gravitate closely around Paxillus involutus.
The colour of the spore print is thought to be important for the species recognition, so it should be thoroughly noted when freshly deposited. The crystal that occur in the rhizomorphs are also considered important so any Paxillus collection must contain fruitbodies with preserved basal mycelium.
Reaction with ammonia solution is used to separate some of the species. It has been proven in other bolete genera that the ammonia reaction has little (if any) taxonomic value. However, it has not been evaluated in Paxillus and it should be tested systematically.
Paxillus albidulus Šutara
Similar to the other species of Paxillus involutus complex, not yet known enough and distinguished on the account of the whitish colouration of the cap, stipe, flesh and the basal mycelium, and the pileipellis hyphae mostly less than 5 μm broad.
Distribution. Not yet understood. Described and so far only known from coniferous forests in the former Czechoslovakia. Should be looked for.
I am still not hosting any photos of this species.
Henrici, A. 2004. A key to Paxillus s. l. in Europe. – Field Mycology 5(3): 87–88.
Šutara, J. 1992. Paxillus albidulus, a new species of the family Paxillaceae. – Ceská Mykologie 45(4): 129–133.