Armillaria ectypa

Description

Armillaria ectypa, known as the marsh honey fungus, is a distinctive mushroom with unique ecological and morphological features. Belonging to the Physalacriaceae family within the Desarmillaria subgenus, it is characterized by mushrooms that lack a ring or annulus on their stalks. What sets A. ectypa apart is its remarkable bioluminescence, observable in both its mycelium and occasionally in its fruitbodies, notably in the gills.

This species holds endangered status in Great Britain under the Wildlife and Countryside Act 1981 and is listed on the provisional European red data list, emphasizing its rarity and the urgent need for conservation measures. Due to its specific habitat requirements and limited distribution, conservation efforts are critical to safeguard its populations in natural habitats. Its inclusion in international conservation agreements highlights not only its ecological importance but also its vulnerability.

Common names: Marsh Honey Fungus.

Mushroom Identification

1. Cap

   Can reach up to 10 cm (4 in) in diameter, initially convex and later flattening with age. Often develops a depressed center, with a dark brown, scaly center and a yellowish-brown to brown outer region that varies with moisture.

2. Gills

   Narrow and decurrent (running down the stem), initially whitish and maturing to cream, buff, or pinkish hues. They are visible through the thin structure of the cap.

3. Stem

   Up to 10 cm (4 in) tall, cylindrical, and slightly swollen at the base. It shares the same coloration as the cap and lacks mycelial cords at its base.

4. Habitat

   It can grow in dense clumps or singly.

5. Spore Print

   White.

6. Basidiospores

   6.7-9.5 x 5.5-6.5 μm, subglobose to ellipsoidal, not amyloid.

7. Habitat

   This species thrives in specific habitats, primarily sphagnum bogs and peatlands with low nitrogen availability and alkaline microhabitats. It plays a crucial role in nutrient cycling within wetlands, decomposing decaying peat moss and other bryophytes.

8. Distribution

   Endemic to Eurasia, A. ectypa is found in various countries including Great Britain, Poland, Germany, and extending into Asia in countries like China and Japan. It prefers waterlogged environments such as raised bogs, peat mires, and alkaline fens where sphagnum mosses, sedges, and reeds are abundant.

Synonyms

• Agaricus ectypus Fr. (1821)

• Clitocybe ectypa (Fr.) Gillet (1874)

• Camarophyllus ectypus (Fr.) P.Karst. (1879)

• Omphalia ectypa (Fr.) Quél. (1886)

• Armillariella ectypa (Fr.) Singer (1943)

Photo sources:

Photo 1 - Author: Pärismaalane (CC BY-SA 4.0)

Photo 2 - Author: Lukas from London, England (CC BY-SA 2.0)