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 vernalis Watling
Known to me from the descriptions in the literature. Cap depressed to funnel shaped, sometimes flattened, smooth or scaly, pale ochraceous, ochraceous brown, yellowish brown, cap margin inrolled, tomentose to smooth. Stipe stout, cylindrical, not exuding droplets at the base. Gills forking, pale ochraceous, darker at maturity, bruising brownish. Flesh pale yellowish, turning more reddish when exposed to air. Spore print vinaceous red. Spores 7.5–10 × 5–6 μm. Hyphae of the cap cuticle mostly less then 5 μm in diameter.
Habitat. Hedges and under solitary trees in parks and gardens. Mycorrhizal with deciduos trees.
Distribution. American species, in Europe suspected as introduced and so far known only from the British Isles, Denmark and Estonia. Should be looked for.
Similarity. Compare closely with the rest of the species in Paxillus and especially with Paxillus obscurosporus with which it shares the vinaceous hues of the spore print.
I still do not have photos of this species. Colour photograph of the first British record is presented by Kibby (2008). Some photographs of American collections may be seen on the internet. Please, follow the links below.
Henrici, A. 2004. A key to Paxillus s. l. in Europe. – Field Mycology 5(3): 87–88.
Bresinsky, A. 2006. Observations on Mycobiota in Estonia. – Folia Cryptogamica Estonica 42: 1–9. (available online)
Kibby, G. 2008. Fungal portraits. No 33: Paxillus vernalis – first British record. – Field Mycology 9(1): 3–4.
Knudsen, H. & Vesterholt, J. [eds.]. 2008. Funga Nordica. Nordsvamp, Kopenhagen.