Exidia blackening (Exidia nigricans)
- Department: Basidiomycota (Basidiomycetes)
- Subdivision: Agaricomycotina (Agaricomycetes)
- Class: Agaricomycetes (Agaricomycetes)
- Subclass: Auriculariomycetidae
- Order: Auriculariales (Auriculariales)
- Family: Exidia (Exidiaceae)
- Genus: Exidia (Exidia)
- Species: Exidia nigricans (Exidia blackening)
or Exidia plana
Exidia nigricans (With.)
Fruit body: 1-3 cm in diameter, black or black-brown, at first rounded, then fruiting bodies merge into one lumpy medullary mass extending up to 20 cm, adherent to the substrate. The surface is shiny, smooth or wavy-wrinkled, covered with small dots. When dry, they become hard and turn into a black crust covering the substrate. They can swell again after rains.
Flesh: dark, transparent, gelatinous.
Spore powder: white. Spores are elongated, 12-16 x 4-5.5 microns.
Taste: negligible. Smell: neutral.
The mushroom is inedible, but not poisonous.
It grows on fallen and dried branches of deciduous and broad-leaved trees, sometimes covering a large area.
It is widely distributed throughout the northern hemisphere, including throughout Russia.
It appears in spring in April-May and grows until late autumn under favorable conditions.
Exidia spruce (Exidia pithya) – grows on conifers, fruit bodies are smooth. Some mycologists believe that spruce exsidia and blackening exsidia are one species.
Exidia ferruginous (Exidia glandulosa) – grows only on broad-leaved species (oak, beech, hazel). Fruit bodies never merge into a common mass. The spores of the glandular exidia are slightly larger.