How to identify Pleated Whitegill

To correctly identify Pleated Whitegill (Rhodocollybia butyracea), 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 typically 3-10 cm in diameter, convex to broadly convex or nearly flat in maturity, often with a central depression. The margin can be wavy or somewhat pleated (hence 'Pleated Whitegill'). The surface is smooth, moist to greasy or buttery to the touch, especially when wet. Color varies significantly from pale tan, buff, or grayish-brown to dark reddish-brown, often fading with age or in dry conditions. The center is usually darker.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   The gills are adnexed to nearly free, close to crowded, and narrow. They are typically white to cream-colored, sometimes developing a yellowish tint with age. They often appear somewhat 'pleated' or wavy near the stem attachment.

3. 3

   Stem

   Length, shape, surface, and any ring.

   The stem is 4-10 cm long and 0.5-1.5 cm thick, often tapering slightly upwards or downwards, sometimes with a slightly swollen base. It is typically hollow or stuffed, fibrous, and brittle. The surface is smooth or finely striate, often concolorous with the cap or paler, sometimes with a whitish, fuzzy base (mycelium).

4. 4

   Flesh

   Color, texture, and bruising reaction.

   The flesh is thin, white, and rather soft. It does not change color when cut or bruised.

5. 5

   Fruiting body

   Overall growth pattern.

   The fruiting body is a typical agaric (gilled mushroom) with a cap, gills, and a central stem.

6. 6

   Habitat

   Where it grows and on what substrate.

   Saprobic, growing on decaying organic matter, typically in leaf litter or on well-rotted wood (often buried) in coniferous and deciduous forests. It can be found growing solitarily, scattered, or in small clusters.

Key Facts

Cap surfaces

Smooth, moist, greasy/buttery, often wrinkled/pleated margin.

Growth Form

Solitary, scattered, or in small clusters.

Spore Print

White to pale cream.

Body color

Cap variable (tan, buff, grayish-brown to reddish-brown), gills white to cream, stem concolorous or paler.

Odor

Mild, sometimes slightly rancid or indistinct.

Flesh bruises

No color change.

Height

4-10 cm

Cap Diameter

3-10 cm

Fruit body characteristics

• Gill attachment: Adnexed to nearly free.
• Stem shape: Cylindrical, often tapering slightly, sometimes with a slightly swollen base.
• Stem surface: Smooth or finely striate, often with whitish mycelium at the base.
• Ring: Absent.
• Stem cross-section: Hollow or stuffed.

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