Armillaria tabescens

What You Should Know

Armillaria tabescens is a species of mushroom in the Armillaria genus. It has a convex and smooth cap that typically ranges from tan to brownish. The gills are attached to the stem and are initially white, but darken with age. The stem is typically white and fibrous. It has been traditionally used in Chinese medicine for its potential health benefits. Armillaria tabescens contains polysaccharides and other compounds that may have immune-boosting and anti-inflammatory properties. It is widely distributed throughout North America, Europe, and Asia. It is typically found growing on the roots and base of trees, and is commonly associated with hardwoods such as oak, maple, and birch.

While Armillaria tabescens is not poisonous, it is generally considered to be of low edibility due to its tough texture and bitter taste. Some people may experience gastrointestinal upset if they consume this mushroom. Also, there is no evidence to suggest that Armillaria tabescens has any psychedelic properties. While some mushrooms, such as Psilocybe cubensis, contain psychoactive compounds like psilocybin and psilocin, A. tabescens does not contain any known psychoactive substances.

Armillaria tabescens is a pathogenic fungus that can cause root rot in trees, which can lead to their decline or death. It is also capable of forming large underground networks called "rhizomorphs" that can extend for several meters, allowing it to spread easily between trees. The mycelium of the fungus is bioluminescent.

Other names: Ringless Honey Mushroom, German (Ringloser Hallimasch).

Armillaria tabescens Mushroom Identification

1. Cap

   The cap is 1.18 to 3.94 inches (3 to 10 cm) wide when it's fully grown. At first, it's convex, but as it gets older, it becomes flatter or even slightly indented. It's dry to the touch, and when it's young, it's covered in darker brown scales. As it matures, the scales move towards the center and may be arranged in a radial pattern. The color of the mushroom varies from tan to tawny brown, cinnamon brown, or yellow. Sometimes, the edges become slightly lined.

2. Gills

   Running down the stem or nearly so; close or nearly distant; short-gills frequent; whitish with pinkish hints; sometimes bruising or discoloring slightly pinkish to brownish.

3. Stem

   1.97 to 3.15 inches (5 to 8 cm) long; 0.20 to 0.39 inches (0.5 to 1 cm) thick; tapering to base; bald and pale grayish to brownish near apex, darker brown and nearly hairy below; without a ring.

4. Flesh

   Whitish to watery tan; not changing when sliced.

5. Odor and Taste

   Odor not distinctive; taste bitter, or not distinctive.

6. Spore Print

   White.

7. Habitat

   It is found in the eastern United States, ranging from the Mid-Atlantic states to the south, and from mid-Texas and Oklahoma to parts of New England. The fungi grow on the root wood of hardwood trees and can appear at the base of living trees, on or between exposed or underground roots, or near dead stumps. They act as decomposers but can also function as parasites or symbiotes with living trees.

8. Microscopic Features

   Spores 6–9 x 4–5 µm; ellipsoid; with a prominent apiculus; smooth; hyaline in KOH; inamyloid. Cheilocystidia 25–40 x 5–10 µm; clavate to subclavate, cylindric, or somewhat irregular (occasionally nearly lobed and/or digitate); septate; thin-walled; smooth; hyaline in KOH. Pleurocystidia not found. Basidia 2- and 4-sterigmate; not basally clamped. Pileipellis a collapsing trichoderm of hyaline to brownish, frequently septate elements 2.5–7.5 µm wide.

Armillaria tabescens Look-Alikes

1. Omphalotus illudens

   Similar to A. tabescens in terms of size and decurrent gills growing in clusters from dead trees, but can be easily distinguished by their bright orange color.

2. Galerina marginata

   Small to medium-sized brown mushrooms growing in clusters on dead wood. Can be mistaken for young A. tabescens if not paying attention, but can be distinguished by its brown spore print and the presence of a ring.

Armillaria tabescens Synonyms and Varietes

• Agaricus buxeus Persoon (1828), Mycologia europaea, seu complet omnium fungorum in variis europaeae regionibus detectorum enumeratio, 3, p. 190

• Agaricus caespitosus (Berkeley) Berkeley & M.A. Curtis (1867) [1869], The journal of the linnean Society, botany, 10(45), p. 287

• Agaricus gymnopodius Quelét fide Pearson & Dennis (1948)

• Agaricus irrufatus N. Lund (1845), Conspectus hymenomycetum circa Holmiam crescentium, p. 13

• Agaricus monadelphus Morgan (1883), Journal of the Cincinnati Society of natural history, 6(1), p. 69

• Agaricus socialis de Candolle (1815), Flore française ou description succincte de toutes les plantes qui croissent naturellement en France, Edn 3, 6, p. 48

• Agaricus tabescens Scopoli (1772), Flora carniolica, Edn 2, 2, p. 446 (Basionyme)

• Armillaria mellea var. exannulata Peck (1893) [1892], Annual report of the New York state Museum of natural history, 46, p. 54

• Armillaria mellea var. gymnopodia (Bulliard) Quélet (1886), Bulletin de la Société mycologique de France, 1(3), p. 81

• Armillaria mellea var. tabescens (Scopoli) Rea & Ramsbotton (1917) [1916], Transactions of the British mycological Society, 5(3), p. 352

• Armillaria socialis (de Candolle) Fayod (1889), Annales des sciences naturelles, botanique, série 7, 9, p. 232

• Armillariella tabescens (Scopoli) Singer (1943), Annales mycologici, edii in notitiam scientiae mycologicae universalis, 41(1-3), p. 19

• Clitocybe aquatica Banning & Peck (1891) [1890], Annual report of the New York state Museum of natural history, 44, p. 68

• Clitocybe gymnopodia (Bulliard) Gillet (1874), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 162

• Clitocybe gymnopodia var. socialis (de Candolle) Costantin & L.M. Dufour (1891), Nouvelle flore des champignons, Edn 1, p. 27

• Clitocybe monadelpha (Morgan) Saccardo (1887), Sylloge fungorum omnium hucusque cognitorum, 5, p. 164

• Clitocybe parasitica Willcox (1901), Oklahoma Agricultural Experiment Station. Bulletin, 49, p. 18

• Clitocybe socialis (de Candolle) Gillet (1874), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 159

• Clitocybe tabescens (Scopoli) Bresadola (1900), Fungi tridentini, novi vel nondum delineati, 2(14), p. 84, tab. 197

• Collybia tabescens (Scopoli) Gillet (1884), Tableaux analytiques des Hyménomycètes de France (Alençon), p. 68

• Dendrosarcus caespitosus (Berkeley) Kuntze (1898), Revisio generum plantarum, 3, p. 463

• Desarmillaria tabescens (Scopoli) R.A. Koch & Aime (2017), BMC Evolutionary Biology, 17(33), p. 12

• Flammula gymnopodia (Bulliard) Quélet (1873), Mémoires de la Société d'Emulation de Montbéliard, série 2, 5, p. 346(335)

• Fungus tabescens (Scopoli) Kuntze (1898), Revisio generum plantarum, 3, p. 480

• Gyrophila socialis (de Candolle) Quélet (1896) [1895], Compte rendu de l'Association française pour l'avancement des sciences, 24(2), p. 617, pl. 6, fig. 4

• Lentinus caespitosus Berkeley (1847), in W.J. Hooker, The London journal of botany, 6, p. 317

• Monodelphus caespitosus (Berkeley) Murrill (1911), Mycologia, 3(4), p. 192

• Naucoria gymnopodia (Bulliard) Migula (1912), Kryptogamen-flora von Deutschland, Österreich und der Schweiz, Band III. Pilze, 2(2), p. 534

• Omphalia mellea var. gymnopodia (Bulliard) Quélet (1886), Enchiridion fungorum in Europa media et praesertim in Gallia vigentium, p. 20

• Omphalia socialis (de Candolle) Quélet (1886), Enchiridion fungorum in Europa media et praesertim in Gallia vigentium, p. 21

• Panus caespitosus (Berkeley) Fries (1851), Novae symbolae mycologicae. Fasciulus primus, sistens fungos in peregrinis terris a botanicis danicis nuper collectos, p. 23

• Pholiota gymnopodia (Bulliard) A.F.M. Reijnders (1998), Persoonia, 17(1), p. 113

• Pleurotus caespitosus (Berkeley) Saccardo (1887), Sylloge fungorum omnium hucusque cognitorum, 5, p. 352

• Pocillaria caespitosa (Berkeley) Kuntze (1891), Revisio generum plantarum, 2, p. 865

• Tricholoma sociale (de Candolle) Sartory & L. Maire (1918), Synopsis du Genre Tricholoma, p. 57

Sources:

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