Rubroboletus legaliae

Description

Rubroboletus legaliae, previously known as Boletus splendidus, B. satanoides, and B. legaliae is a basidiomycete fungus of the family Boletaceae. It is poisonous, with predominantly gastrointestinal symptoms, and is related to Rubroboletus satanas.

This is a large to medium sized, boletoid, without veil and ring. Stipe solid, with surface usually covered with granules or network. Flesh variously colored, changing or not when exposed to air. Tubes are easily separable from each other, not tearing apart. Pores are usually small and rounded. Grows with oak (Quercus) and beech (Fagus) are often on neutral to acid soils.

Distribution in Europe is widespread but uncommon, more often encountered in the south.

Mushroom Identification

1. Cap

   Up to 12 cm, at first hemispherical, later convex to flat-convex or almost flat, initially finely velvety, then smooth, at first almost white, grayish to dark grey, grayish brown, ochraceous or beige, with pinkish tint at the cap margin, later beige with irregular pink or vinaceous spots, often entirely dingy pink, dark pink or pinkish vinaceous.

2. Stipe

   Club-shaped or cylindrical, in the uppermost part bright to dark yellow, downwards orange-red to red or pinkish-red, with fine orange-red or red network, in the lower pat with fine red or pinkish-red granules, stipe surface blueing when handled.

3. Flesh

   Pale yellow, sometimes with reddish spots in the stipe base, blueing when exposed to air. Tubes yellow, blueing when injured. Pores red to orange, blueing when bruised.

4. Odor and Taste

   The smell of hay, persistent when the fungus is dried. Taste slightly acid. Spores 9–15 × 4–6 μm, ratio 1.9–3.

5. Microscopy

   Pileipellis trichodermium of interwoven septate hyphae of cylindrical, finely incrusted cells.

6. Chemical Reactions

   Hyphae of the flesh in the stipe base amyloid with Melzer’s solution.

7. Habitat

   Warm broadleaf forests, mycorrhizal with oaks (Quercus) or beech (Fagus).

Look-Alikes

1. Rubroboletus satanas

   Found in broad-leaved woodland on calcareous soil, has a whiter cap that turns brownish-ochre, lacking the overall reddish tones in maturity. It has a more nauseating smell, and it is poisonous, possibly deadly. Molecular study of the holotype of Rubroboletus spinari has demonstrated its conspecifity with Rubroboletus legaliae.

2. Rubroboletus rubrosanguineus

   Very similar, but is found under conifers.

3. Rubroboletus rhodoxanthus

   It is distinguished on the account of its yellow flesh which blues mostly in the cap and remains unchanged in the stipe.

History

Boletus legaliae was described by Czech mycologist Albert Pilát in 1968. It is named after the French mycologist Marcelle Le Gal. Boletus splendidus as described by Charles-Édouard Martín in 1894 is a synonym. The description of Boletus satanoides was too vague to be ascribed to any actual species. Boletus legaliae was transferred to the genus Rubroboletus in 2015 by Marco Della Maggiora and Renzo Trassinelli.

Photo sources:

Photo 1 - Author: Xth-Floor (CC BY-SA 3.0)

Photo 2 - Author: Lukas from London, England (CC BY-SA 2.0)

Photo 3 - Author: Lukas from London, England (CC BY-SA 2.0)

Photo 4 - Author: Lukas from London, England (CC BY-SA 2.0)

Photo 5 - Author: Lukas from London, England (CC BY-SA 2.0)