How to identify Blue-staining Bolete

To correctly identify Blue-staining Bolete (Cyanoboletus pulverulentus), check each of these features in order. Misidentification is the most common cause of mushroom poisoning, so cross-reference multiple sources.

Step-by-step identification

1. 1

   Cap

   Shape, color, surface texture, and diameter.

   Convex to flat, 4-12 cm in diameter, brown to reddish-brown, velvety surface.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   Pore surface is yellow initially, turning olive-yellow then intensely blue when touched.

3. 3

   Stem

   Length, shape, surface, and any ring.

   Cylindrical, smooth or slightly pruinose, yellow to brown, no reticulation present.

4. 4

   Flesh

   Color, texture, and bruising reaction.

   Yellowish, changing almost instantly to a dark blue or black upon bruising or cutting.

5. 5

   Fruiting body

   Overall growth pattern.

   Typical bolete shape with a fleshy cap and spongy pore surface underneath.

6. 6

   Habitat

   Where it grows and on what substrate.

   Often found in deciduous or mixed forests, particularly near oak or beech.

Key Facts

Cap surfaces

Velvety, dry to slightly tacky

Growth Form

Solitary or small groups

Spore Print

Olive-brown

Body color

Brown cap with yellow pores

Odor

Mild

Flesh bruises

Instant deep blue/black

Height

5 to 12 cm

Cap Diameter

4 to 12 cm

Fruit body characteristics

• Gill attachment: Adnate to depressed
• Stem shape: Cylindrical, occasionally tapered
• Stem surface: Pruinose, smooth
• Ring: Absent
• Stem cross-section: Solid, bruising blue

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