Winter Russula (Russula cremoricolor)

🏷️ Description

Russula cremoricolor, also known as the winter russula, is a striking yet mildly toxic gilled mushroom found in the mixed forests of coastal California and the Pacific Northwest. This species dazzles with its colorful cap variations, ranging from creamy yellow or whitish to vivid red, making field identification both fascinating and challenging.

⚠️ Toxicity: Russula cremoricolor is poisonous. Even small amounts can cause intestinal distress, so it should never be consumed. Its acrid taste is a natural deterrent.

🧬 Fascinating Facts:

• DNA studies confirmed that the red morph (once misidentified as Russula silvicola or Russula emetica) is genetically identical to the cream-colored form, making them color variants of the same species.

• The species name “cremoricolor” means “cream-colored” but doesn’t fully capture the vivid red form commonly found in the wild.

🔎 Identification

🧢 Cap:

• Size: 1.18 to 3.94 inches (3 to 10 cm) wide.

• Shape: Starts convex, becoming flat or shallowly depressed with age.

• Texture: Sticky when wet, smooth overall.

• Color: Either creamy yellow/whitish or bright red. Red and cream caps may grow near each other!

• Margin: Often lined at maturity.

• Peeling: Cap skin peels halfway to the center.

🌿 Gills:

• Attachment: Adnexed to attached.

• Color: White, aging to creamy.

• Spacing: Close to nearly distant.

📏 Stem:

• Size: 0.79 to 3.94 inches (2 to 10 cm) long; 0.39 to 0.98 inches (1 to 2.5 cm) thick.

• Color & Texture: White, smooth, and dry.

• Flesh: White, with no color change when cut.

👃👅Odor & Taste:

• Odor: Not distinctive.

• Taste: Strongly acrid, a sharp clue to avoid consumption.

🔬 Spores:

• Spore Print: White.

• Microscopic Features: Spores: 7.5–10.5 x 6–8.5 µ, with isolated warts and sparse connectors. Pileocystidia: Cylindric to subfusiform, ochraceous-refractive in KOH, positive in sulphovanillin.

🌳 Habitat: Mycorrhizal; grows in mixed forests (favoring tanoak and hardwoods over pine); appears gregariously or singly from late fall through spring. It is a regular sight during the cooler months, often brightening forest floors with its vivid cap colors.

Photo sources:

Photo 1 - Author: Torrey Brownell (CC BY 4.0)

Photo 2 - Author: Mark Wagner (CC BY 4.0)

Photo 3 - Author: Alan Rockefeller (CC BY-SA 4.0)

Photo 4 - Author: Garth Harwood (CC BY 4.0)