Exidia nigricans
Encyclopedia
Exidia nigricans is a jelly fungus in the family Auriculariaceae
. It is a common, wood-rotting species throughout the northern hemisphere, typically growing on dead attached branches of broadleaf trees. It has been much confused with Exidia glandulosa
.
in 1776, based on a phrase name published by Dillenius in 1741. It was subsequently considered a synonym of Exidia glandulosa, until Donk revised species concepts in 1966 and placed it in synonymy with Exidia plana. Changes in the starting point for fungal nomenclature has made Exidia plana illegitimate, however, leaving Exidia nigricans as the earliest name for the species.
Molecular research has shown that Exidia glandulosa and E. nigricans, though similar, are distinct.
. It is said to be based on a folk belief that witches milk cows at night and scatter the butter around. Clearly the butter they produce does not look appetizing. In Sweden, it is apparently known as "Troll smör" ("Troll's butter") for the same reason.
. The basidia are ellipsoid, septate, 15-25 x 8-13 µm
. The spores are allantoid (sausage-shaped), 14-19 x 4.5-5.5 µm.
Tremella foliacea
is usually a warmer, lighter brown, but can sometimes be dark sepia to black. Its fruitbodies are gelatinous, but usually foliaceous (with flattish lobes or fronds) and never have warts or pegs on the surface. It is common and occurs on both broadleaf trees and conifers.
Auriculariaceae
The Auriculariaceae are a family of fungi in the order Auriculariales. Species within the family were formerly referred to the "heterobasidiomycetes" or "jelly fungi", since many have gelatinous basidiocarps that produce spores on septate basidia. Around 100 species are known worldwide. All are...
. It is a common, wood-rotting species throughout the northern hemisphere, typically growing on dead attached branches of broadleaf trees. It has been much confused with Exidia glandulosa
Exidia glandulosa
Exidia glandulosa is a jelly fungus in the family Auriculariaceae. It is a common, wood-rotting species in Europe, typically growing on dead attached branches of oak. The fruit bodies are up to wide, shiny, black and blister-like, and grow singly or in clusters...
.
Taxonomy
The species was originally described from England as Tremella nigricans by WitheringWilliam Withering
William Withering was an English botanist, geologist, chemist, physician and the discoverer of digitalis.-Introduction:...
in 1776, based on a phrase name published by Dillenius in 1741. It was subsequently considered a synonym of Exidia glandulosa, until Donk revised species concepts in 1966 and placed it in synonymy with Exidia plana. Changes in the starting point for fungal nomenclature has made Exidia plana illegitimate, however, leaving Exidia nigricans as the earliest name for the species.
Molecular research has shown that Exidia glandulosa and E. nigricans, though similar, are distinct.
Witches' Butter
Both Dillenius (1741) and Withering (1776) gave the English name for this species as "Witches' butter", though this name has subsequently also been applied to other gelatinous fungi, including Exidia glandulosa and the yellow Tremella mesentericaTremella mesenterica
Tremella mesenterica is a common jelly fungus in the Tremellaceae family of the Agaricomycotina...
. It is said to be based on a folk belief that witches milk cows at night and scatter the butter around. Clearly the butter they produce does not look appetizing. In Sweden, it is apparently known as "Troll smör" ("Troll's butter") for the same reason.
Description
Exidia nigricans forms dark sepia to blackish, rubbery-gelatinous fruit bodies that are button-shaped and around 2 cm (0.78740157480315 in) across. The fruitbodies occur in clusters and quickly coalesce to form effused, irregular masses 10 cm (3.9 in) or more across. The upper, spore-bearing surface is shiny and dotted with small pimples or pegs. The individual fruitbodies are each attached to the wood at the base. The spore print is white.Microscopic characters
The microscopic characters are typical of the genus ExidiaExidia
Exidia is a genus of fungi in the family Auriculariaceae. Species are saprotrophic, growing on dead attached or recently fallen wood, and produce gelatinous basidiocarps . The fruit bodies are variously pustular, lobed, button-shaped, or top-shaped...
. The basidia are ellipsoid, septate, 15-25 x 8-13 µm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
. The spores are allantoid (sausage-shaped), 14-19 x 4.5-5.5 µm.
Similar species
Exidia nigricans and E. glandulosa are frequently confused. The two are similar, but E. glandulosa produces discrete, top-shaped fruitbodies that rarely if ever coalesce. They are indistinguishable microscopically, but DNA research indicates they are distinct.Tremella foliacea
Tremella foliacea
Tremella foliacea is a species of fungus producing brownish, frondose, gelatinous basidiocarps . It is widespread, particularly in north temperate regions, and is parasitic on other species of fungi , that grow on dead attached and recently fallen branches of broadleaf trees and conifers...
is usually a warmer, lighter brown, but can sometimes be dark sepia to black. Its fruitbodies are gelatinous, but usually foliaceous (with flattish lobes or fronds) and never have warts or pegs on the surface. It is common and occurs on both broadleaf trees and conifers.