How to identify Winter Polypore

To correctly identify Winter Polypore (Lentinus brumalis), 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 2-10 cm in diameter, circular to kidney-shaped, and often depressed in the center. Its color varies from yellowish-brown to dark brown, sometimes with a reddish tint, and it is usually covered with fine, dark, appressed scales or hairs, especially when young. The margin is often inrolled when young and becomes wavy or lobed with age. The surface is dry and dull.

2. 2

   Gills

   Attachment to stem, color, and spacing.

   The underside features a poroid surface, but these are not true gills. Instead, they are angular, radially arranged pores that often appear gill-like due to their elongated, labyrinthine, or even tooth-like structure. They are white to cream-colored, becoming yellowish with age, and are decurrent (running down the stem). The pore mouths are relatively large, 0.5-2 mm wide.

3. 3

   Stem

   Length, shape, surface, and any ring.

   The stem is central or slightly eccentric, 2-8 cm long and 0.3-1 cm thick. It is tough, cylindrical, and often tapers towards the base. The color is similar to the cap, ranging from yellowish-brown to dark brown, and it is typically covered with fine, dark scales or hairs, especially towards the base. It is solid and fibrous.

4. 4

   Flesh

   Color, texture, and bruising reaction.

   The flesh is thin, tough, and white to cream-colored, with a leathery consistency. It does not change color when bruised or cut.

5. 5

   Fruiting body

   Overall growth pattern.

   The fruiting body is a tough, leathery mushroom with a central or slightly eccentric stem and a cap that can range from convex to funnel-shaped.

6. 6

   Habitat

   Where it grows and on what substrate.

   Saprobic, growing on dead hardwood logs, branches, and stumps, particularly on oak, beech, birch, and alder. It can be found solitary or in scattered groups.

Key Facts

Cap surfaces

Dry, dull, finely scaly or hairy

Growth Form

Solitary or scattered

Spore Print

White

Body color

Yellowish-brown to dark brown (cap and stem), white to cream (pores)

Odor

Mild, mushroomy

Flesh bruises

No

Height

2-8 cm

Cap Diameter

2-10 cm

Fruit body characteristics

• Gill attachment: Decurrent (pores)
• Stem shape: Cylindrical, sometimes tapering towards base
• Stem surface: Finely scaly or hairy, similar color to cap
• Ring: Absent
• Stem cross-section: Solid

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