Leccinum variicolor

Description

Leccinum variicolor is an edible mushroom with a dark brown-black, often mottled cap. White stem flesh stains pink high and blue-green low, often faintly & slowly. Salt & pepper stem. White or buff pores bruise slowly brown.

Salt & pepper stem. Firm white flesh will often stain slightly pink on top and green at the base, especially in the cap and upper stem. Stem usually tapers toward the pores. No noticeable smell. Likes birch and aspen in wet, acidic forests. There is a rare form with a pale cap.

Common names: Mottled Bolete.

Mushroom Identification

1. Cap

   Various shades of grey or dark gray-brown (a rare off-white rare form also exists) usually (but not always) variegated/mottled with a radial pattern of lighter spots or stripes, the broadly convex cap of Leccinum variicolor is finely tomentose (woolly or very finely scaly) when young but can become very much smoother as it ages. Caps range from 5 to 15cm in diameter when fully expanded.

   The cap flesh is white and often turns slightly pinkish beneath the cap cuticle when it is broken or cut.

2. Tubes and pores

   The small, circular tubes are broadly adnexed (but not adnate) to the stem; they are 0.7 to 1.8cm long, very pale grey to creamy-white, and terminate in pores approx. 0.5mm in diameter that are similarly colored, often with yellowish-brown spots.

   When bruised, the pores gradually turn brownish.

3. Stem

   White or buff and 7 to 15cm tall, the stems of Leccinum variicolor are 2 to 3cm in diameter, tapering towards the apex. Immature specimens have barrel-shaped stems; at maturity, most stems are more regular in diameter but tapering slightly towards the apex. The stem flesh is white but sometimes turns pinkish in the upper section when it is cut or broken, while near to the stem base the cut flesh turns greenish-blue.

   Dark brown or black scabers (woolly scales standing out from the pale background of the surface) cover the whole of the stem.

4. Spores

   Fusiform, thin-walled,14-19 x 5-6.5µm, inamyloid.

5. Spore print

   Ochraceous buff.

6. Odor and Taste

   The faint smell and taste are pleasant but not particularly distinctive.

7. Chemical Tests

   NH4OH (Ammonia): No reaction on cap or flesh.

   KOH: No reaction on the cap. Made a slight indentation on stem and cap flash with no color reaction.

   FeSO4 (Iron Salts): No reaction on the cap. Stem and cap flesh turn greenish.

Look-Alikes

1. Leccinum versipelle

   Has a much more orange cap; it bruises blue-green in the stem base.

2. Leccinum scabrum

   Very variable in cap color, although usually a lighter brown than the Mottled Bolete; its stem flesh does not turn blue or blue-green when cut or broken.

History

The Mottled Bolete was described in 1969 by British mycologist Roy Watling, who at that time was working in Edinburgh, Scotland.

Synonyms of Leccinum variicolor include Krombholziella variicolor (Watling) Šutara, Boletus variicolor (Watling) Hlavácek, Leccinum variicolor f. atrostellatum Lannoy & Estadès, Leccinum variicolor f. sphagnorum Lannoy & Estadès, and Leccinum variicolor var. bertauxii Lannoy & Estadès.

Leccinum, the generic name, comes from an old Italian word meaning fungus. The specific epithet variicolor is a reference to the very variable cap coloring of this species.

Photo sources:

Photo 1 - Author: Tim Strater from Rotterdam, Nederland (CC BY-SA 2.0)

Photo 2 - Author: Tatiana (CC BY-SA 4.0)

Photo 3 - Author: Nina Filippova (CC BY-SA 4.0)

Photo 4 - Author: Dmitriy Bochkov (CC BY-SA 4.0)

Photo 5 - Author: Jerzy Opioła (CC BY-SA 4.0)