Frosty Bonnet (Mycena adscendens)
Description
⚪ The Mycena adscendens, or Frosty Bonnet, is a tiny yet charming white mushroom that often appears as if dusted with sugar-like granules. Its delicate cap starts out hood-shaped and flattens as it matures, revealing grooves along the gills. 🌨️
The gills are broad, distantly spaced, and either free or barely attached to the stem, sometimes forming a slight collar around it. The stem is slender, hollow. At the base, the stem enlarges into a small, disc-like structure that helps the mushroom attach to fallen twigs, hazel nuts, and woody debris. 🌰🍂
You'll find this mushroom scattered or growing in small groups on decaying hardwoods, especially after wet weather, from early summer to winter. It can be spotted across Europe, the Pacific coast of the U.S., and even Turkey.
🍽️ Though its edibility is unknown, it’s more a treat for the eyes than for the plate! 🌲
This mushroom’s frosty appearance is often confused with similar species like Mycena stylobates and Mycena alphitophora, but its distinct granular cap and disc-like base make it stand out. 🌟
📜 The species now known as Mycena adscendens was first named Agaricus adscendens by Wilhelm Gottfried Lasch in 1829 in what is now Germany. Dutch mycologist Maas Geesteranus gave it its current name in 1981.
Mushroom Identification
🍄 Cap: This mushroom boasts a tiny white cap measuring just 2.0-7.5 mm in diameter. Starting off hemispherical to hood-shaped, it flattens as it matures, revealing delicate grooves corresponding to the gills below. The surface is sometimes coated with glistening particles, remnants of the partial veil. Initially grayish with a white margin, it turns fully white as it ages. The cap's flesh is delicate, thin, and see-through. It looks frosted, like sugar, but this appearance may fade as it ages.
🍃 Gills: The gills are narrow, translucent-white, and adnexed (slightly attached) to the stem, with minutely fringed edges. You’ll find between 7 and 13 gills, spaced distantly as the mushroom ages. Some gills may form a collar-like structure around the stem, known as a pseudocollarium.
📏 Stem: The stem is threadlike, hollow, and usually 0.4-2.0 cm long. It may be slightly curved, with a hairy, white, disk-like base that attaches to wood or decaying organic material. The apex is whitish and smooth, while the lower portion is gray and covered in sparse hairs.
🔬 Microscopic Features:
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Spores: Broadly ellipsoid, 8.0-10.5 x 4.0-6.0 µm, amyloid (stains blue-black in iodine).
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Cheilocystidia: Variable in shape, often fuse-shaped with needle-like projections, sometimes forked.
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Spore Print: White.
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Clamp connections are abundant in the hyphae.
🌳 Habitat: Mycena adscendens thrives on fallen branches of hardwoods and conifers, often appearing in groups after rainy weather. Look for this tiny beauty throughout the mushroom season.
⚠️ Edibility: While its edibility is unknown, Mycena adscendens is tiny and insubstantial, making it unlikely to be a sought-after culinary find.
🔍 Fun Fact: This mushroom is often overlooked due to its tiny size but can be fascinating under a microscope, where its unique features, like the spiny cheilocystidia, are revealed!
Look-Alikes
1️⃣ Mycena alphitophora
Lacks a swollen or disc-like stem base.
2️⃣ Mycena stylobates
Larger and sturdier fruit body, lacks granules on the cap.
3️⃣ Mycena cryptomeriicola
Non-amyloid spores, lacks clamp connections.
4️⃣ Mycena nucicola
Has four-spored basidia, rare clamp connections, and narrower spores (4.2–5 μm).
5️⃣ Mycena occulta
Does not form a pseudocollarium, lacks clamps, and has densely protuberant terminal cells in the cap cuticle.
Synonyms and Varietes
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Agaricus adscendens Lasch (1829)
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Agaricus farinellus Feltgen (1906)
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Agaricus tenerrimus Berkeley (1836)
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Mycena adscendens var. rickiana Raithelhuber (1984)
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Mycena farinella (Feltgen) Saccardo & Trotter (1912)
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Mycena tenerrima (Berkeley) Quélet (1872)
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Mycena tenerrima var. carpophila J.E. Lange (1914)
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Prunulus tenerrimus (Berkeley) Murrill (1916)
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Pseudomycena tenerrima (Berkeley) Cejp (1930)
Photo sources:
Photo 1 - Author: Alan Rockefeller (CC BY-SA 4.0)
Photo 2 - Author: Alan Rockefeller (CC BY-SA 4.0)
Photo 3 - Author: Alan Rockefeller (CC BY-SA 4.0)
Photo 4 - Author: Michel Langeveld (CC BY 4.0)