How to identify Honey Mushroom

To correctly identify Honey Mushroom (Armillaria ostoyae), 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.

   Caps are typically 3-15 cm (1.2-6 inches) in diameter, convex to broadly convex or nearly flat with age, often with a central umbo. The color varies from yellowish-brown to reddish-brown, often darker towards the center. The most distinctive feature is the presence of numerous, small, dark brown to blackish, erect scales (fibrils) on the cap surface, especially when young, which become sparser or disappear with age, particularly towards the margin. The margin is often incurved when young and may be striate (lined) in older specimens.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   Gills are adnate to slightly decurrent, close to crowded, and initially white to cream, becoming yellowish or pinkish-buff with age, often developing rusty brown spots. They are covered by a partial veil when young.

3. 3

   Stem

   Length, shape, surface, and any ring.

   The stem is 5-20 cm (2-8 inches) long and 1-3 cm (0.4-1.2 inches) thick, central or eccentric, tapering slightly towards the base or sometimes swollen. It is fibrous and tough, especially towards the base. The color is similar to the cap, often paler above the ring and darker below. A prominent, persistent, cottony-membranous ring (annulus) is present on the upper part of the stem, often with a yellowish, cottony margin and a dark, often spore-stained underside. Below the ring, the stem surface is typically covered with dark, woolly scales or fibrils, which are a key distinguishing feature from other Armillaria species.

4. 4

   Flesh

   Color, texture, and bruising reaction.

   The flesh is white, firm, and thick, especially in the cap. It does not change color when cut or bruised. It has a mild, sometimes slightly bitter taste and a mushroomy odor.

5. 5

   Fruiting body

   Overall growth pattern.

   The fruiting bodies of Armillaria ostoyae typically grow in dense clusters, often numbering in the dozens or hundreds, emerging from the base of trees, stumps, or buried wood. They are robust and fleshy.

6. 6

   Habitat

   Where it grows and on what substrate.

   Armillaria ostoyae is a parasitic and saprobic fungus, growing on living trees (especially conifers like fir, spruce, and pine, but also hardwoods like oak and maple), stumps, and buried wood. It causes white rot. It is often found in large clusters at the base of infected trees or on dead wood.

Key Facts

Cap surfaces

Dry, scaly (especially when young)

Growth Form

Clustered, gregarious

Spore Print

White to cream

Body color

Yellowish-brown to reddish-brown

Odor

Mild, mushroomy

Flesh bruises

No

Height

5-20 cm (2-8 inches)

Cap Diameter

3-15 cm (1.2-6 inches)

Fruit body characteristics

• Gill attachment: Adnate to slightly decurrent
• Stem shape: Cylindrical, sometimes tapering towards base or slightly swollen
• Stem surface: Fibrous, scaly below the ring
• Ring: Present, persistent, cottony-membranous, often with dark underside
• Stem cross-section: Solid, becoming fibrous

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