How to identify Viscid Larch Bolete

To correctly identify Viscid Larch Bolete (Suillus viscidus), 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 3-12 cm (1.2-4.7 inches) in diameter, convex to broadly convex, becoming plano-convex or almost flat with age. It is notably viscid (slimy) to glutinous, especially when wet, and often dries to a shiny finish. The color ranges from yellowish-brown, greyish-brown to olive-brown. The margin is often incurved when young, becoming wavy with age, and sometimes features remnants of a veil.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   Not gilled; instead, it has a porous hymenium. The pore surface is yellowish to greenish-yellow, becoming brownish-orange with age. Pores are angular and radially elongated, 0.5-1 mm wide. Tubes are decurrent (running down the stem), concolorous with the pores, and 7-15 mm deep. The pore surface may stain greenish-blue when bruised, though this reaction can be slow or subtle.

3. 3

   Stem

   Length, shape, surface, and any ring.

   The stem is 4-10 cm (1.6-3.9 inches) long and 1-2.5 cm (0.4-1 inch) thick, often tapering slightly towards the base or equal. It is whitish or yellowish above the ring, becoming brownish to greyish below, and typically covered in granular dots (glandular dots) which darken with age. It possesses a membranous, whitish veil that leaves a distinct, persistent, often upward-curving ring (annulus) on the upper part of the stem, which can become dark from falling spores.

4. 4

   Flesh

   Color, texture, and bruising reaction.

   The flesh is thick, soft, and yellowish-white, sometimes darkening to a dingy yellow or brownish when cut or bruised, particularly in the stem base. It may show a slight blueing reaction in some parts, but this is usually faint or absent.

5. 5

   Fruiting body

   Overall growth pattern.

   The fruiting body is typically robust, growing solitary or scattered, but sometimes in clusters. It is a bolete, meaning it has pores instead of gills.

6. 6

   Habitat

   Where it grows and on what substrate.

   Typically found growing on the ground, singly or in scattered groups, exclusively under larch (Larix) trees, usually in mossy areas or needle litter in coniferous or mixed forests. It forms an obligate ectomycorrhizal association with larch.

Key Facts

Cap surfaces

Viscid to glutinous, drying shiny; yellowish-brown to olive-brown.

Growth Form

Solitary, scattered, or in small groups.

Spore Print

Olive-brown to cinnamon-brown.

Body color

Overall yellowish-brown to olive-brown cap, yellowish pores, whitish to brownish stem with granular dots.

Odor

Mild and pleasant; some describe it as slightly fruity.

Flesh bruises

Faintly greenish-blue on pores, sometimes subtly bluish in cap flesh, otherwise yellowish-white to dingy yellow.

Height

4-10 cm (1.6-3.9 inches) for stem.

Cap Diameter

3-12 cm (1.2-4.7 inches).

Fruit body characteristics

• Gill attachment: Not gilled; tubes are decurrent (running down the stem).
• Stem shape: Cylindrical or slightly tapering towards the base.
• Stem surface: Whitish to yellowish above ring, brownish below, covered with brownish granular dots.
• Ring: Present; a persistent, membranous, whitish to brownish annulus, often darkly stained with spores.
• Stem cross-section: Solid

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