Trametes gibbosa

What You Should Know

Trametes gibbosa is a polypore mushroom that causes white rot. The upper surface is usually gray or white but may be greenish in older specimens due to algal growth. Elongated pores are located on the under-surface.

It is found on hardwood, fallen trunks, and stumps, with a preference for beech. It has also been observed on hazelnut trees, Laburnum, Ulmus, Populus, hornbeams, and maple. It is widely distributed throughout Europe.

The combination of three features makes identification unmistakable: the bumpy hump at the point where it attaches to the wood, its almost never rounded pores, which appear elongated and form an irregular, sometimes even lamellar pattern, and the green coloring of its slightly felty upper side that appears sooner or later and is caused by algae growth.

Trametes gibbosa is often inhabited by insect larvae, whose activity shows up in the form of crumbly granules in the immediate vicinity.

Other names: Lumpy Bracket, Outkovka hrbatá (Czech Republic), Puklet Læderporesvamp (Danish), Witte bultzwam (Dutch), Tramète bossue (French), Gebuckelte Tramete/Buckeltramete (German), Púpos egyrétűtapló (Hungarian), Bøkekjuke (Norwegian), Wrośniak garbaty (Polish), Trúdnikovec hrbatý (Slovakian), Grbasta ploskocevka (Slovenian), Korkticka (Swedish).

Trametes gibbosa Mushroom Identification

1. Fruit Bodies

   Annual basidiomata, bracketed, semicircular, imbricate, and measuring from 5 to 20 cm of length, per 1-4 cm of thickness; pileus surface grooved, zoned, villous, tuberculate, later becoming glabrous; of ochraceous-cream color, green due to algal presence; obtuse and rounded edge.

2. Hymenium

   White-cream pores, with elongated pores, often sinuous, 1 to 5 mm long and up to 1 mm broad; the tubules are whitish, mono or pluri-stratified.

3. Flesh

   The flesh is dense, crusty, hard, whitish, sometimes yellowish.

4. Spores

   4-5 * 2-2.5 μm, cylindrical, depressed on one side, elongated at the base, colorless..

5. Spore Print

   Whitish.

6. Habitat

   It grows from Summer to Autumn, on dry and fallen trunks, on stumps of deciduous trees, mainly on birches, elms, beeches, hornbeams, and maples. Causes white rot of wood.

7. Microscopy

   Trimitic hyphal structure with hyaline, fibulate and ramified generative hyphae, the connective hyphae have many ramifications, very numerous are also the skeletal hyphae, without septa; cystidia and cystidioles are absent; basidia are tetrasporic cylindrical or cylindrical-clavate, hyaline, with basal clamp connections, 15-20 × 4-6 µm; slender sterigmata; the basidiospores are hyaline, smooth, cylindrical or oblong and bent, inamylod, 4-5 × 1,8-2,3 µm.

Trametes gibbosa Medicinal Properties

Antiinflammatory/vasoprotective activity

Research has shown that polysaccharides isolated from the fruit bodies of T. gibbosa can confer a protective effect to rat blood vessels in the carrageenan assay, suggesting their possible use in pathological disease conditions leading to endothelial damage (Czarnecki and Grzybek, 1995). Carrageenans are a family of linear sulphated polysaccharides from seaweed that, when injected into the pleural cavity of various animals, cause an inflammatory reaction.

The study demonstrated that intravenous administration of T. gibbosa polysaccharides neutralized changes in blood vessel permeability, decreased total protein levels in the pleural effusion, increased the number of neutrophils and eosinophils while reducing the number of lymphocytes in the surrounding blood.

Antitumor activity

Polysaccharides extracted from the mycelial culture of T. gibbosa and administered intraperitoneally into white mice at a dosage of 300 mg/kg inhibited the growth of Sarcoma 180 and Ehrlich solid cancers by 80% and 90%, respectively (Ohtsuka et al., 1973).

The petroleum ether and ethyl acetate extract of T. gibbosa were shown to be cytotoxic to human cervix epitheloid carcinoma cell lines (Hela) and human hepatoma cell lines (SMMC-7721) using the MTT-dye assay. The methanol extract, however, showed weak activity when compared with the flavonoid quercetin (Ren et al., 2006).

Recently, it was shown that organic extracts of T. gibbosum (as Daedalea gibbosa) mycelium are effective in inhibiting the growth of K562 cells, a laboratory model of human chronic myelogenous leukemia (Yassin et al., 2008).

Antiviral effects

Methanol extracts from T. gibbosa were shown to have mild inhibitory effects (i.e., <40% inhibition) on HIV-1 reverse transcriptase activity in vitro (Mlinarič et al., 2005).

Trametes gibbosa Similar Species

1. Trametes hirsuta

   Has roundish and smaller pores, thin context, pileus surface much velvety to the touch, and more elongated spores.

2. Trametes suaveolens

   Similar to coloration but having, however, great and rounded pores, and the flesh emitting a good smell of anise, clearly bigger spores.

3. Trametes betulina

   Similar to pileus appearance but with greyer or brown-ochraceous colors, and having, furthermore, gilled hymenium.

Trametes gibbosa Taxonomy and Etymology

In 1796 Christiaan Hendrick Persoon described this species and named it Merulius gibbosus. In 1836 Swedish mycologist Elias Magnus Fries renamed it to the current scientific name.

The genus name "Trametes" comes from the prefix tram- meaning thin. The specific epithet gibbosa means humped or rounded.

Trametes gibbosa Synonyms

• Agarico-suber scalptum Paulet 1793

• Bulliardia virescens Lázaro Ibiza 1916

• Daedalea gibbosa (Persoon) Persoon 1801

• Daedalea virescens (Lázaro Ibiza) Sacc. & Trotter 1925

• Lázaro Ibiza 1916

• Lenzites gibbosa (Persoon) Hemmi 1939

• Merulius gibbosus Pers. 1795

• Polyporus gibbosus (Persoon) P. Kummer 1871

• Polystictus kalchbrenneri (Fr.) Cooke 1886

• Pseudotrametes gibbosa (Persoon) Bondartsev & Singer 1944

• Pseudotrametes gibbosa forma tenuis (Pilát)

• Trametes crenulata Berk. 1854

• Trametes gibbosa forma tenuis Pilát 1940

• Trametes gibbosa var. tenuis (Pilát)

• Trametes kalchbrenneri Fr. 1868

• Trametes nigrescens Lázaro Ibiza, 1916

Sources:

Photo 1 - Author: Jean-Pol GRANDMONT (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Michel Langeveld (Creative Commons Attribution-Share Alike 4.0 International)

Photo 3 - Author: Michel Langeveld (Creative Commons Attribution-Share Alike 4.0 International)

Photo 4 - Author: Michel Langeveld (Creative Commons Attribution-Share Alike 4.0 International)

Photo 5 - Author: Jean-Pol GRANDMONT (Creative Commons Attribution-Share Alike 2.5 Generic)