Ganoderma sessile

Common Name: Ganoderma sessile

Habitat and Growth Characteristics:

Annual, sessile to pseudostipitate: Growing on dead hardwood trees, logs, stumps, and at the base of living trees, particularly oaks. It is a saprophytic fungus.

Fruiting Body: The cap is 4-8 cm overhanging, 3-16(20) cm wide, semi-circular to irregularly reniform (kidney-shaped), dimidiate to flabelliform (fan-shaped), convex to flattened, often dented near the point of attachment. The cap forms a varnished, glossy, and shiny surface that can become radially wrinkled, with colors ranging from entirely reddish-orange to dark reddish-brown or dark red, sometimes with various zones of color like tan, yellowish-brown, orange-brown, pale red, or grayish, and a whitish margin.

Pore Surface: Initially whitish to pale brown, becoming medium to dark brown with age, darkening further when bruised.

Pores: Round to angular, irregular, small, with 5-7 per millimeter.

Tube Layers: Up to 7 mm long.

Stem:

Stem often absent, and if present, it is short (up to 5-2 cm), usually smaller in diameter than the cap, stout, often misshapen, and can be centrally or laterally attached. It has a glossy surface, ranging from tawny to reddish-brown.

Flesh:

Flesh is corky, tenacious but not woody, creamy, pale tan to pale flesh brown, with concentric growth zones, but no deposits or melanoid bands.

Odor and Taste: Indistinct.

Spore Print: Dark reddish-brown.

Hyphal System: Trimitic, with generative hyphae being coiled and hyaline (clear), skeletal hyphae with thickened walls and brown, and binding hyphae with slightly thickened walls and pale yellow, thin-walled, about 1-2 μm in diameter.

Spores: Approximately ellipsoid, truncated at the apex, ornamented with interparietal pillars giving the impression of a double wall, with a finely echinate inner layer but appearing smooth, brown, non-reactive in Melzer's reagent, measuring 9.7-14 x 5.2-8.4 μm on average, with a mean size of 11.4 x 6.6 μm.

Cystidia and Sterile Elements: Absent.

Pileipellis: Composed of a palisade of club-shaped cells with the presence of hyphal loops.

Growth Habit: Solitary, gregarious, or in overlapping clusters.

Period: Typically from May to November, with the possibility of persistence throughout the year.

Edibility: Non-edible.

Medicinal properties:
Ganoderma sessile, like other mushrooms in the Ganoderma genus, is often associated with various potential medicinal properties in traditional and folk medicine. However, it's important to note that while there is a long history of use and anecdotal claims regarding its health benefits, scientific research is ongoing, and more concrete evidence is needed to confirm these properties. Some of the potential medicinal properties attributed to Ganoderma mushrooms, including Ganoderma sessile, include:

1. Immune System Support: Ganoderma mushrooms are often used as immunomodulators, which means they may help regulate and strengthen the immune system. They are believed to enhance the body's natural defense mechanisms.

2. Anti-Inflammatory Effects: Compounds found in Ganoderma mushrooms, such as triterpenoids and polysaccharides, have shown anti-inflammatory properties in some studies. These effects may have applications in conditions associated with chronic inflammation.

3. Antioxidant Activity: Ganoderma mushrooms are rich in antioxidants, which can help combat oxidative stress and free radical damage in the body. Antioxidants are associated with various health benefits.

4. Potential Anti-Tumor Activity: Some studies suggest that Ganoderma mushrooms, including Ganoderma sessile, may have anti-cancer properties. They could inhibit the growth of cancer cells and promote cancer cell apoptosis (cell death).

5. Cardiovascular Health: Ganoderma mushrooms are believed to have a positive impact on cardiovascular health. They may help lower blood pressure, reduce cholesterol levels, and improve blood circulation.

6. Liver Health: Traditional Chinese medicine often uses Ganoderma mushrooms for liver support. They may aid in the detoxification process and protect the liver from damage.

7. Anti-Bacterial and Anti-Viral Effects: Compounds in Ganoderma mushrooms are thought to have antimicrobial properties and could help fight certain bacterial and viral infections.

8. Adaptogenic Properties: Ganoderma mushrooms are classified as adaptogens, which means they may help the body adapt to stress and maintain balance in various systems.

9. Anti-Diabetic Effects: Some studies have suggested that Ganoderma mushrooms may have a role in regulating blood sugar levels and improving insulin sensitivity.

10. Neuroprotective Potential: There is ongoing research into the potential neuroprotective properties of Ganoderma mushrooms, which could have implications in conditions related to brain health.

Chemical Reactions: The cap and flesh turn instantly black when treated with KOH (potassium hydroxide).

Remarks: Ganoderma sessile is characterized by its absent or rudimentary stem, concentric zoned flesh, finely echinate spores, and its growth on hardwoods. It has a beautiful, glossy cap in shades of dark red. Like other Ganoderma species, its pore surface darkens when bruised, and its spores appear to have a double wall.

G. curtisii, a related species, differs in having a longer stem relative to cap diameter, non-zoned flesh, but with parallel melanoid bands, and roughly echinate spores.

In the northeastern United States, G. lucidum was a name given to glossy Ganoderma species. Genetic studies have reorganized these species, and G. sessile was also considered part of the G. lucidum complex.