Boletus pinophilus

Description

Boletus pinophilus is an edible basidiomycete mushroom of the genus Boletus. The skin of the cap is dry, matte and can be colored from maroon to chocolate brown with a reddish tint. It is thicker than other porcini-like boletes and is gelatinous. These characteristics distinguish it visually from relatives edible Boletus species.

The fungus grows predominantly in coniferous forests on sandy soils, forming symbiotic ectomycorrhizal associations with living trees by enveloping the tree's underground roots with sheaths of fungal tissue.

For many years, Boletus pinophilus was considered a subspecies or form of the porcini mushroom Boletus edulis. In 2008, B. pinophilus in western North America were reclassified as a new species, Boletus rex-veris.

Common names: Pine Bolete, Pinewood King Bolete, Netherlands (Denneneekhoorntjesbrood), Czech Republic (Hřib borový), Kiefernsteinpilz (German), France (Cèpe des pins), Poland (Borowik Sosnowy).

Mushroom Identification

1. Cap

   3.15 to 8.66 inches (8 to 22 cm) at maturity; convex in the button stage, becoming broadly convex to nearly flat; greasy to tacky; bald; often shallowly wrinkled in places; brownish red to reddish brown; sometimes with a whitish bloom when young.

2. Pore Surface

   White to whitish at first, becoming yellowish to brownish yellow and eventually olive; not bruising; pores "stuffed" at first; with 2–4 circular pores per mm at maturity; tubes to 0.79 inches (2 cm) deep.

3. Stem

   3.15 to 7.09 inches (8 to 18 cm) long; 1.18 to 3.15 inches (3 to 8 cm) thick; swollen and club-shaped when young, becoming club-shaped or equal; finely whitish-reticulate over at least the upper portion; whitish or pale brownish; basal mycelium white.

4. Flesh

   White; solid; unchanging when sliced, or staining slightly pinkish.

5. Odor and Taste

   Taste nutty; odor not distinctive.

6. Spore Print

   Olive to brownish.

7. Habitat

   Boletus pinophilus is widespread in Europe, Asia and North America. It forms ectomycorrhizal relationships with pine (Pinus), fir (Abies), and spruce (Picea). It can, therefore, be located wherever those trees grow, particularly with Scots pine in Britain, preferring the poor, acidic, and sandy soils associated with coniferous forests. It appears to favor Pinus, while the form of the mushroom occurring in association with Abies and Picea has been labeled Boletus pinophilus var. fuscoruber. However, it is not confined to coniferous trees and may also be found fruiting in deciduous forests, such as under chestnut trees. Fruiting bodies can occur singly, or in small groups throughout the summer and autumn months, although they are known to appear as early as April in Italy.

Look-Alikes

1. Boletus edulis

   Has a yellow-brown cap and grows in oak forests.

2. Boletus betulicola

   Has a grayish-nut-brown surface cap and grows in birch forests.

3. Boletus reticulatus

   Has a gray-brown cap and a mesh pattern on the surface of the stem. Grows in oak forests.

Boletus pinophilus Edibility

This mushroom can be used fresh, preserved, dried, and cooked like other edible boletes. It is highly regarded and can be quite expensive in central Mexico, and is often sold dried there. The flesh is white, soft in mature specimens, and does not change color upon bruising. The taste and smell are pleasant.

Fresh mushrooms are up to 90% water, and rich in carbohydrates. Unsaturated alcohols are a major component of the aroma of porcini mushrooms; 1-Octen-3-ol, 2-octen-1-ol, 3-Octanone, (E)-2-octenal, oct-1-en-3-one and 1,7,7-trimethyl-heptan-2-one, 2-propenoic acid and 1,3-octadiene are the main volatile compounds in B. pinophilus. Boletus pinophilus is known to be a bioaccumulator of the heavy metals mercury, cadmium and selenium. To reduce exposure, authorities recommend avoiding mushrooms from polluted areas such as those near mines, smelters, roadways, incinerators and disposal sites. Furthermore, pores should be removed as they contain the highest concentrations of pollutants.

History

Italian naturalist Carlo Vittadini was the first to recognise the pine bolete as a distinct taxon, describing it as Boletus edulis var. pinicola in 1835. It was raised to species status (as Boletus pinicola) by Antonio Venturi in 1863. Pier Andrea Saccardo treated it as a variety of Boletus aestivalis in 1910. It gained its current name in 1973, described by Czech mycologists Albert Pilát and Aurel Dermek.

The specific epithet is a mix of Latin pinus "pine", and Ancient Greek philus "loving".

Synonyms

• Boletus aestivalis var. pinicola (Vittad.) Sacc. 1910

• Boletus edulis f. pinicola (Vittad.) Vassilkov 1966

• Boletus edulis forma pinicola (Vittad.) Vassilkov 1966

• Boletus edulis subsp. pinicola (Forst) Gilb.

• Boletus edulis var. pinicola Vittad. 1835

• Boletus pinicola (Vittad.) A. Venturi 1863

• Boletus pinophilus f. fuscoruber (Forq.) Estadès & Lannoy (2001)

• Boletus pinophilus Pilát & Dermek (1973) var. pinophilus

• Boletus pinophilus var. fuscoruber (Forq.) Cetto (1987)

• Boletus pinophilus var. viridicaerulescens Estadès & Lannoy (2001)

• Dictyopus edulis var. fuscoruber Forqu 1890

• Oedipus edulis var. fuscoruber Bat.

• Tubiporus edulis subsp. pinicola Maire

Video

Photo sources:

Photo 1 - Author: Ak ccm (CC BY 3.0)

Photo 2 - Author: Paffka (CC BY-SA 3.0)

Photo 3 - Author: Aorg1961 (CC BY-SA 4.0)

Photo 4 - Author: Roy Turnbull (CC BY-SA 2.0)

Photo 5 - Author: Lukas (CC BY-SA 2.0)