Sutorius junquilleus

Description

Sutorius junquilleus is a species of bolete fungus in the family Boletaceae. It is found in Europe, Central America, North America, and India, where it grows in deciduous and mixed forests. Initially uniformly yellow in color, all external surfaces of the fruit body undergo a variety of discolorations as it matures.

Cap flesh may have a greenish tint. Yellow stem bruises blue & then resolves to brown. Stem usually has no netting. Cap flesh may taste a little acidic or astringent. Likes oak & pine.

German mycologist Franz Joseph Kallenbach first described this mushroom scientifically in 1923, from collections made in Germany. A year later, Kallenbach published a more thorough description.

Some authors have historically considered Sutorius junquilleus — a species described by Lucien Quelet in 1897—to be a synonym, including first Gilbert and Leclair in 1942, and Rolf Singer in 1947. Reid has suggested that differences are due only to climatic conditions, with the red colors appearing in conditions of lower temperature. It was transferred to the genus Neoboletus in 2015.

Synonyms: Boletus Junquilleus, Neoboletus Pseudosulphureus, Boletus Pseudosulphureus.

Mushroom Identification

1. Cap

   Up to 15 cm, hemispherical then convex, flat-convex or almost flat, initially dry, velvety, later smooth, lemon to bright yellow, yellowish ochraceous, in young fruitbodies more or less uniformly colored, later spotted brownish, strongly blueing when bruised, then blackening.

2. Stem

   Stipe clavate, concolorous with the cap, covered with scattered yellow to brownish granules, surface blueing, and then blackening when bruised.

3. Flesh

   Flesh lemon yellow, sometimes with dark red spots in the stipe base, blueing when exposed to air. Tubes lemon yellow to yellow with olivaceous tint, blueing when exposed to air.

4. Pores

   Pores concolorous with the tubes, blueing when bruised.

5. Smell & Taste

   Smell not distinctive. Taste slightly acid.

6. Spores

   12–16.5 × 4.5–6 μm, ratio 2.2–2.7.

7. Pileipellis (the cap cuticle)

   A trichodermium of interwoven septate hyphae of cylindrical, not incrusted cells.

8. Chemical reactions

   Hyphae of the stipe base inamyloid.

9. Habitat

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

10. Similar Species

    Compare with Boletus luridiformis var. discolor, which has similarly colored fruitbodies, but features orange pores.