Species flashcards

Description

Cap: 5–15 cm across, hemispherical when young, later convex to spreading. The margin is initially infolded and later downturned. Surface finely felty to velvety, dry and matte; dark brown, dark grey, olive-brown to blackish, becoming darker with age.

Tubes and pores: The tube layer is thick, adnate to the stem or curving slightly upward before it. Pores narrow, initially greyish-pink, later dark brown like the cap; bruising may cause blue-green and then blackish discolouration.

Stem: 5–12 cm tall and 1–3.5 cm thick, stout, cylindrical or ventricose, sometimes bulbously enlarged toward the base. Finely granular and cap-coloured on a whitish to brownish background; the stem base always remains paler and whitish.

Flesh: Firm, white to pale cream. When cut, it may become faintly pinkish or blue-green, then slowly blacken. Smell and taste are usually indistinct, sometimes sourish or unpleasant.

Spores: Spore print rusty brown with a reddish-brown tint. Spores 13–19 × 7–9 µm, ellipsoid, smooth and thick-walled.

Occurrence: A mycorrhizal species of acidic mountain soils in spruce, fir and other conifer woodland, more rarely broadleaf woodland. It occurs with spruce, fir, two-needle pines and beech from June to October.

Edibility: Treated as poisonous or unsuitable for consumption. Rare and protected in Hungary, with a conservation value of 10,000 HUF; it must not be collected.

Lookalikes: Usually recognisable by its uniformly dark cap, stem and darkening spore-bearing layer in age. It may resemble the bay bolete, but that species usually has a shinier cap and pores that blue more strongly when bruised.

Note: Porphyrellus combines Greek porphýra (“purple dye”) with the Latin diminutive -ellus, referring to dark reddish-brown to purplish shades. Porphyrosporus derives from Greek porphýra (“purple”) and sporá (“spore”), referring to the dark reddish-brown spore print.

Species description: Elias Magnus Fries and Johan Hök first described the species as Boletus porphyrosporus in 1835. Jean-Edouard Gilbert transferred it to Porphyrellus in 1931.

Taxonomy

1. PhylumBasidiomycota
2. ClassAgaricomycetes
3. OrderBoletales
4. FamilyBoletaceae
5. GenusPorphyrellus

• Species: Porphyrellus porphyrosporus
• Authority: (Fr. & Hök) E.-J. Gilbert (1931)
• English name: Dusky bolete
• Ecological status: mycorrhizal
• Edibility: poisonous