Semi-white mushroom (Hemileccinum impolitum) photo and description

Semi-white mushroom (Hemileccinum impolitum)

  • Department: Basidiomycota (Basidiomycetes)
  • Subdivision: Agaricomycotina (Agaricomycetes)
  • Class: Agaricomycetes (Agaricomycetes)
  • Subclass: Agaricomycetidae (Agaricomycetes)
  • Order: Boletales
  • Family: Boletaceae
  • Genus: Hemileccinum
  • Species: Hemileccinum impolitum (Semi-white mushroom)

Other names: 

  • Flying half white

  • Half white mushroom

  • Boletus yellow

  • Boletus impolitus

Boletus impolitus semi-white mushroomThe recent revision by mycologists of the Boletaceae family has led to the fact that some species migrated from one genus to another, and many even acquired a new - their own - genus. The latter happened with a semi-white fungus, which previously belonged to the genus Borovik (Boletus), and now has a new "surname" Hemileccinum.


The cap is 5-20 cm in diameter, in young mushrooms it is convex, then cushion or prostrate. The skin is velvety at first, then smooth. The color is clay with a reddish tint or light gray with an olive tint.

The tubules are loose, golden yellow or pale yellow, turn greenish yellow with age, do not change the color when pressed or darken slightly (do not turn blue). The pores are small, angularly rounded.

Spore powder olive-ocher, spores 10-14 * 4.5-5.5 microns in size.

The leg is 6-10 cm high, 3-6 cm in diameter, squat, first tuberous-swollen, then cylindrical, fibrous, slightly rough. In the upper part it is yellow, at the base it is dark brown, sometimes with a reddish belt or spots, without a mesh.

The flesh is thick, pale yellow, near the tubules and intensely yellow in the stem. Basically, the color on the cut does not change, but sometimes a very slight pinking or blue discoloration is observed after a while. The taste is sweetish, the smell is slightly carbolic, especially at the base of the stem.


A heat-loving species, it is found in coniferous forests, as well as under oak, beech, in the South, often in beech-hornbeam forests with dogwood undergrowth. Prefers calcareous soils. Fruiting from late May to autumn. The fungus is quite rare, fruiting is not annual, but sometimes abundant.


Inexperienced mushroom pickers can be confused with porcini mushroom (Boletus edulis), with maiden's pain (Boletus appendiculatus). It differs from them in the smell of carbolic acid and the color of the pulp. There is a danger of confusion with an inedible deep-rooting pain (Boletus radicans, syn: Boletus albidus), which has a light gray cap, lemon yellow stem and pores that turn blue when pressed, and has a bitter taste.


The mushroom is very tasty, the unpleasant smell disappears during boiling. In pickled form it is not inferior to white, has a very attractive light golden color.


Due to its rarity, it requires the protection of habitats and careful treatment.