Scaly Ink Cap (Coprinopsis variegata)

🏷️ Description

Meet Coprinopsis variegata, affectionately known as the Scaly Ink Cap or Feltscale Inky Cap. This eye-catching mushroom, clad in patchy felty scales, appears in woodland clusters in early summer, offering a striking yet ephemeral beauty. While not recommended for the dinner table, this species boasts fascinating ecological behaviors and a curious taxonomic history.

Coprinopsis variegata is a standout among inky caps. With its dramatic felty cap, ephemeral beauty, and unusual bacterial predation, it’s a treasure for naturalists and mycologists alike. Just don’t eat it—especially not with wine!

🧬 Taxonomy: Originally described as Coprinus variegatus in 1873 by American mycologist Charles Horton Peck, this mushroom was later joined by two lookalikes: C. ebulbosus and C. quadrifidus. Decades of confusion followed until a detailed 1979 analysis consolidated the trio into one species: Coprinopsis variegata.

🔎 Identification

🍄 Cap

• Size: (3 to 8 cm) 1.18 to 3.15 inches wide; may reach up to (12 cm) 4.7 inches in extreme cases

• Shape: Starts oval, becomes bell-shaped, then flattens with age, edges often curl upward or split

• Color & Texture: Whitish to yellowish-tan scales from a universal veil cover a gray to brown cap; often grooved (striate) with age

🌿 Gills

• Attachment: Free or narrowly attached

• Color: Begin white, turn grayish to black, then dissolve into black ink (deliquesce)

📏 Stem

• Size: (4 to 13 cm) 1.57 to 5.12 inches long, up to (1 cm) 0.39 inches thick

• Color: White, felty or woolly texture

• Structure: Hollow, uniform thickness, may end in a rimmed bulb embedded in wood

• Ring: Lacks a true ring but may have a cottony sheath at the base

🍖 Flesh

• Thin, whitish, and unchanging when cut

• Odor: Not distinctive

• Taste: Bitter; not recommended for consumption

⚫ Spore print: Black or blackish-brown

🔬 Microscopic Features

• Spores: (6–10 × 4–5.5 µm), ellipsoid, smooth, with germ pore

• Basidia: (18–22 × 6–7 µm), 4-spored

• Pleurocystidia: Dimorphic—either thin-walled and subutriform or thick-walled metuloids (up to 5 µm thick)

• Cheilocystidia: Ellipsoid, visible in young specimens

• Clamp connections: Present in all tissues

🌎 Habitat & Ecology

• Type: Saprobic – feeds on decaying hardwood

• Substrate: Logs, buried wood, or rich leaf litter

• Season: June to July (rarely later)

• Distribution: Eastern North America, from southern Canada to the southeastern U.S., east of the Great Plains

• Fruiting Habit: Grows in dense clusters, emerging from brown mats of mycelial strands (ozonium)

🧬 Bacterial Predator

Coprinopsis variegata doesn't just feast on wood—it can also attack and digest soil bacteria like Pseudomonas and Agrobacterium. Using a chemoattractive response, it directs specialized hyphae to the bacteria, secretes enzymes to digest them, and absorbs the nutrients. This unique predatory behavior allows it to consume entire bacterial colonies in less than 24 hours!

⚠️ Edibility & Toxicity

While C. variegata is technically non-poisonous, it is not recommended for consumption:

• May contain coprine, a compound causing Antabuse-like reactions when consumed with alcohol

• Bitter taste, poor culinary value

• Reported to cause allergic skin reactions and gastric upset

• Warning: Some field guides note it as the "best of the inky caps" for texture and flavor, but this is not a consensus

👀 Look-Alikes

• Coprinopsis atramentaria: Similar size and color, but lacks patchy woolly scales

• Coprinopsis strossmayeri: Shares habitat but has finer veil remnants and a different stem base morphology

📜 Synonyms

• Coprinus variegatus Peck (1873), Bulletin of the Buffalo Society of natural sciences, 1, p. 54

• Coprinus picaceus var. ebulbosus Peck (1891) [1890], Annual report of the New York state Museum of natural history, 44, p. 20

• Coprinus ebulbosus (Peck) Peck (1895), Bulletin of the Torrey botanical Club, 22(12), p. 491

• Coprinus quadrifidus Peck (1898) [1897], Annual report of the New York state Museum of natural history, 50, p. 106

• Coprinus atramentarius var. variegatus (Peck) Rick (1961), Iheringia, série botânica, 8, p. 445

Photo sources:

Photo 1 - Author: Cole Wolf (CC BY 4.0)

Photo 2 - Author: eeyipes (CC BY 4.0)

Photo 3 - Author: David Goldstein (CC BY 4.0)

Photo 4 - Author: Brian Hunt (CC BY 4.0)