How to identify Sulphur Bolete

To correctly identify Sulphur Bolete (Butyriboletus regius), 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.

   The cap is convex, becoming more flattened with age. It is typically 5–15 cm in diameter. The color is usually bright yellow, but can also be reddish-pink or orange-yellow. The surface is smooth and dry, and may be slightly sticky when wet.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   Butyriboletus regius is a bolete, so it has pores instead of gills. The pores are small and round, and bright yellow, bruising blue when handled.

3. 3

   Stem

   Length, shape, surface, and any ring.

   The stem is stout and club-shaped, typically 5–12 cm long and 2–5 cm thick. It is yellow, often with a reddish tint, and may have a fine network of ridges near the top.

4. 4

   Flesh

   Color, texture, and bruising reaction.

   The flesh is thick and yellow. It may stain slightly blue when cut, particularly in the stem.

5. 5

   Fruiting body

   Overall growth pattern.

   The fruit body of Butyriboletus regius is a typical bolete shape, with a cap and a central stem. It is medium to large in size.

6. 6

   Habitat

   Where it grows and on what substrate.

   This mushroom is found in deciduous forests, particularly under oak and beech trees. It is a mycorrhizal fungus, forming a symbiotic relationship with the roots of trees.

Key Facts

Cap surfaces

Smooth, dry, may be slightly sticky when wet

Growth Form

Mycorrhizal

Spore Print

Olive-brown

Body color

Yellow, reddish-pink, or orange-yellow

Odor

Mild and pleasant

Flesh bruises

May stain slightly blue when cut

Height

5-12 cm

Cap Diameter

5-15 cm

Fruit body characteristics

• Gill attachment: Pores instead of gills
• Stem shape: Stout, club-shaped
• Stem surface: Smooth, may have a fine network of ridges near the top
• Ring: Absent
• Stem cross-section: Solid

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