How to identify White Brain Fungus

To correctly identify White Brain Fungus (Exidia thuretiana), 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.

   Not applicable, as it is a resupinate or effused-reflexed jelly fungus without a distinct cap.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   Not applicable, as it is a jelly fungus and does not produce gills.

3. 3

   Stem

   Length, shape, surface, and any ring.

   Not applicable, as it is sessile and lacks a distinct stem.

4. 4

   Flesh

   Color, texture, and bruising reaction.

   Translucent white, gelatinous, and rubbery. No distinct odor or taste.

5. 5

   Fruiting body

   Overall growth pattern.

   Irregularly lobed, convoluted, brain-like or cushion-shaped, often coalescing to form larger masses. Typically 1-5 cm across, but can be larger. Color is translucent white to grayish-white, becoming yellowish or brownish with age or when drying. Surface is smooth and somewhat shiny when moist, becoming dull and opaque when dry. Texture is gelatinous and rubbery when fresh, becoming hard and horny when dry, rehydrating readily.

6. 6

   Habitat

   Where it grows and on what substrate.

   Saprobic, growing on dead deciduous wood, particularly on fallen branches and logs. Favors broadleaf trees such as oak, beech, and hazel. Often found on the underside or sides of logs.

Key Facts

Cap surfaces

Not applicable (no cap)

Growth Form

Effused, resupinate, or cushion-shaped, often coalescing

Spore Print

White

Body color

Translucent white to grayish-white

Odor

Indistinct

Flesh bruises

Does not bruise

Height

Not applicable (sessile)

Cap Diameter

1-5 cm (individual lobes), often coalescing to larger masses

Fruit body characteristics

• Gill attachment: Not applicable (no gills)
• Stem shape: Not applicable (no stem)
• Stem surface: Not applicable (no stem)
• Ring: Not applicable (no ring)
• Stem cross-section: Not applicable (no stem)

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