Pholiota alnicola

🏷️ Description

Pholiota alnicola is an intriguing mushroom that doesn’t quite fit the mold—even among its own genus. While most Pholiota species are scaly and adorned with dramatic pleurocystidia, P. alnicola takes a subtler approach. Belonging to the subgenus Flammula, this saprophytic fungus lacks both cap scales and pleurocystidia, making it a bit of a misfit—but an interesting one at that. Let’s explore this vivid yellow mushroom and its moist, shady world 🌧️🌳.

🧬 Taxonomy & Name Origins

• Scientific name: Pholiota alnicola

• Described by: Elias Magnus Fries (1838 as Agaricus alnicola)

• Transferred to Pholiota: By Rolf Singer in 1949

• Family: Strophariaceae

• Etymology: Pholiota means "scaly," and alnicola refers to its love for Alnus (alder) trees.

🌎 Distribution & Habitat

You’ll find P. alnicola in North America, northern and central Europe, and parts of Asia. While uncommon in Britain and Ireland, it's increasing in prevalence due to alder tree dieback caused by Phytophthora fungi. Look for it in:

• Damp, shaded woodlands

• Beside rivers, lakes, and in alder carrs

• On stumps, fallen trunks, or buried wood of alder, willow, birch, and occasionally conifers

It typically grows in clusters but may appear solitary, especially from late summer to early winter (August to December) depending on region.

🔎 Identification

🧢 Cap

• Size: (0.79 to 3.15 inches) 2 to 8 cm in diameter

• Shape: Convex, becoming broadly convex or nearly flat

• Color: Bright lemon-yellow to sulfur-yellow; darker center often with orange or foxy brown shades

• Texture: Slimy or greasy when wet; smooth or with faint fibers

• Edge: May retain veil fragments

🍂 Gills

• Attachment: Adnate to slightly decurrent

• Color: Lemon-yellow initially, turning cinnamon or rust-brown as spores mature

• Spacing: Crowded

• Covered by: Cortina-like veil in youth

📏 Stem

• Size: (1.57 to 3.15 inches) 4 to 8 cm tall; (0.2 to 0.43 inches) 5 to 11 mm thick

• Color: Lemon-yellow at top, darkening toward rusty-brown base

• Texture: Smooth to slightly fibrous; rarely scaly

• Ring: Pale, often ephemeral ring zone from partial veil

• Flesh: Fibrous and yellow, with orange tones near the base

🥩 Flesh

• Color: Lemon-yellow, deeper orange-brown in lower stem

• Odor: Faintly sweet to earthy or indistinct

• Taste: Bitter

🌰 Spore Print & Microscopy

Spore Print: Rusty brown to tobacco brown

Spores:

• Size: 8.5–12 × 4–6 μm

• Shape: Elliptical, smooth, weakly dextrinoid

• Features: Germ pore present

🔬 Other Microscopy:

• Pleurocystidia absent

• Cheilocystidia diverse

• Subgelatinous cap cuticle

• Clamp connections present

🌟 Unique Features

• Belongs to Subgenus Flammula: Distinguished by slimy caps, lack of pleurocystidia, and dextrinoid spores.

• Antioxidant Activity: Studies show high antioxidant potential in the mycelium, sparking interest for nutraceutical uses.

👀 Look-Alikes

1️⃣ Kuehneromyces mutabilis

• Cap: Two-toned

• Stem: Darker below ring

• Gills: Ochraceous when young

2️⃣ Pholiota flavida

• Spores: Smaller (7–9 × 4–5 μm)

• Taste: Mild

3️⃣ Pholiota malicola

• Spores: 8–11 × 1.5–5.5 μm

• Taste: Mild

🍽️ Edibility

🚫 Not edible. Despite its attractive appearance, Pholiota alnicola is bitter-tasting and potentially harmful, like most scalycaps. It should never be consumed.

🌱 Conservation & Rarity

In parts of Europe, especially Switzerland, this species is considered vulnerable (VU). Its habitat depends on decaying wood in moist conditions—ecosystems that are increasingly under threat.

📜 Synonyms

• Agaricus velatus Schumacher (1803)

• Hypodendrum croceosulphureum Paulet (1808)

• Agaricus alnicola Fries (1821)

• Agaricus hypoxanthus Léveillé (1855)

• Flammula alnicola (Fries) P. Kummer (1871)

• Dryophila alnicola (Fries) Quélet (1886)

• Flammopsis alnicolus (Fries) Fayod (1889)

• Flammula alnicola var. marginalis Peck (1902)

• Flammula sulphurea Peck (1912)

• Gymnopilus alnicola (Fries) Murrill (1917)

• Pholiota pseudohypholoma Velenovský (1921)

• Flammula malicola Kauffman (1926)

• Flammula flavida ss. Bresadola (1930)

• Pholiota malicola (Kauffman) A.H. Smith (1934)

• Pholiota apicrea ss. J.E. Lange (1938)

• Pholiota aromatica P.D. Orton (1960)

Photo sources:

Photo 1 - Author: Hamilton (ham) (CC BY-SA 3.0)

Photo 2 - Author: Jerzy Opioła (CC BY-SA 4.0)

Photo 3 - Author: Jerzy Opioła (CC BY-SA 4.0)

Photo 4 - Author: Jimmie Veitch (jimmiev) (CC BY-SA 3.0)