Auricularia auricula-judae
Encyclopedia
Auricularia auricula-judae, known as the Jew's ear, jelly ear or by a number of other common name
s, is a species of edible Auriculariales
fungus found worldwide. The fruiting body
is distinguished by its noticeably ear-like shape and brown colouration; it grows upon wood, especially elder. Its specific epithet is derived from the belief that Judas Iscariot
hanged himself from an elder tree; the common name "Judas's ear" eventually became "Jew's ear", while today "jelly ear" or other names are sometimes used. The mushroom can be found throughout the year in temperate regions worldwide, where it grows upon both dead and living wood. Although it is not regarded as a choice edible mushroom
in the west, it has long been popular in China, to the extent that Australia exported large volumes of the mushroom to China in the early twentieth century.
While not widely consumed in the west, A. auricula-judae was used in folk medicine as recently as the 19th century for complaints including sore throats, sore eyes and jaundice
, and as an astringent
. Today, the mushroom is still used for medicinal purposes in China, where soups featuring it are used as a remedy for colds; it is also used in Ghana, as a blood tonic. Modern research into possible medical applications have variously concluded that A. auricula-judae has antitumour, hypoglycemic, anticoagulant
and cholesterol
-lowering properties.
, and later (1789) described by Jean Baptiste François Pierre Bulliard
as Tremella auricula-judae. However, the genus Tremella
is now reserved for fungal species that live as parasites
on other fungi. Tremella auricula-judae is now considered a basionym
. In 1791, Bulliard transferred the species to the genus Peziza
. In 1822, Elias Magnus Fries
transferred the species to Exidia
, and, in so doing, sanctioned the name
. In 1860, Miles Joseph Berkeley
described the species as a member of Hirneola, a genus described by Fries in 1848, now considered synonymous with Auricularia. The species was given the name Auricularia auricula-judae in 1888 by Joseph Schröter
. The specific name of A. auricula-judae comprises auricula, the Latin word meaning ear, and Judae, meaning of Judas. Under binomial nomenclature
, a species name can comprise only two words; but the taxonomists responsible for this naming hyphenated the specific name to "bend the rules" and keep the name "within the letter of the law". The name was criticised by mycologist Curtis Gates Lloyd
, who said "Auricularia auricula-Judae is cumbersome and in addition is a slander on the Jews". Though critical of Lucien Marcus Underwood
, saying he "would probably not have known the Jew's ear from the calves' liver", he followed him in using Auricularia auricula, which was in turn used by Bernard Lowy in an article on the entire genus. Despite this, Auricularia auricula-judae is the currently recognised name for the species by many sources, though Auricularia auricula is still occasionally used. As well as the obligate synonyms from Bulliard, Fries and Berkeley, there are numerous other synonymous names
. Mycologist George Willard Martin
, writing in 1943, noted that the species was known by at least 12 binomials
, of which none appeared to be valid, and noted that "the citations given for the various names are extremely erratic". Mycologist Mary F. Barrett attributes "such multiplication of names" to "the wide distribution of the Judas' ear, its ability to grow upon many different kinds of decaying wood, and to its great variation in size, colour and shape".
The fungus is associated with Judas Iscariot
because of the belief that he hanged himself on an elder tree after his betrayal of Jesus Christ. Folklore suggests that the ears are Judas's returned spirit, and are all that are left to remind us of his suicide. The common name
of the fungus was originally Judas's ear, but this was later shortened to Judas ear and, in the late 19th century, shortened again to Jew's ear. Common names for the fungus which refer to Judas can be traced back to at least the end of the 16th century; for instance, in the 17th century, Thomas Browne
wrote of the species:
While the term Jew's meat was a deprecatory term used for all fungi in the Middle Ages, the term is unrelated to the name Jew's ear. A further change of name to jelly ear was recommended in the List of Recommended Names for Fungi. The idea was rejected by mycologist Patrick Harding who considered it "to be the result of political correctness where it is not necessary", and who "will continue to call [the species] Jew's ear", explaining that, while anti-Semitism was commonplace in Britain, the name Jew's ear is in reference to Judas, who was a Jew. However, the name has been adopted in some recent field guide
s. Unrelated common names include the ear fungus, common ear fungus, the Chinese Fungus, the pig's ear, the wood ear, the black wood ear, the tree ear and Kikurage. The species was known as "fungus sambuca" among herbalists, in reference to Sambuca, the generic name for elder.
of A. auricula-judae is normally 3 to 8 cm (1.2 to 3.1 in) across, but can be as much as 12 centimetres (4.7 in). It is distinctively shaped, typically being reminiscent of a floppy ear, though the fruit bodies can also be cup-shaped. It is normally attached to the substrate
by the back surface of the cup, though there can also be a rudimentary stem. The species has a tough, gelatinous, elastic texture when fresh, but it dries hard and brittle. The outer surface is a bright reddish-tan-brown with a purplish hint, often covered in tiny, downy hairs of a grey colour. It can be smooth, as is typical of younger specimens, or undulating with folds and wrinkles. The colour becomes darker with age. The inner surface is a lighter grey-brown in colour and smooth. It is sometimes wrinkled, again with folds and wrinkles, and may have "veins", making it appear even more ear-like.
. The spores can sometimes be seen in a whitish mass on the underside of the fruit body. The species has elongated cylindrical basidia with three transverse septa (internal cross-walls dividing the hyphae). Hairs on the fruit body are from 85 to 100 μm in length, and 5 to 6 μm in diametre. They are hyaline
, lack a central strand and have rounded tips. They do not grow in dense tufts.
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Auricularia auricula-judae grows upon the wood of deciduous
trees and shrubs, favouring elder. In up to 90% of cases, the mushroom is found on elder, but it is often incorrectly assumed to grow exclusively on elder. It has also been recorded on Acer pseudoplatanus (known in the United Kingdom as sycamore), beech
, ash, spindle
, and in one particular case, the sycamore draining board of an old sink in Hatton Garden
. In Australia, it is found in Eucalyptus
woodland and rainforests; in the rainforests, it can grow in very large colonies on fallen logs. It favours older branches, where it feeds as a saprophyte (on dead wood) or a weak parasite
(on living wood), and it causes white rot.
Commonly growing solitarily, it can also be gregarious (in a group) or caespitose (in a tuft). Spores are ejected from the underside of the fruit bodies with as many as several hundred thousand an hour, and the high rate continues when the bodies have been significantly dried. Even when they have lost some 90% of their weight through dehydration, the bodies continue to release a small number of spores. It is found all year, but is most common in autumn. It is widespread throughout temperate
and sub-tropical
zones worldwide, and can be found across Europe, North America, Asia, Australia, South America and Africa. There has been some debate about the appearance of the species in the tropics
; while it has been frequently reported there, Bernard Lowy, in an article on Auricularia, said that "of the specimens I have examined, none could be assigned here".
and rehydrated, sometimes swelling to a very large size. Young specimens are best, but the species is not edible when raw, needing to be cooked thoroughly. The whole fruit body can be eaten, but should be thoroughly washed before cooking. Cooking can sometimes take a comparatively long time. The nutritional content of 100 g (3.5 oz) of dried fungus includes 370 kcal
, 10.6 g of protein, 0.2 g of fat
, 65 g of carbohydrate
, 5.8 g ash
, and 0.03% mg of carotene
. Fresh mushrooms contain about 90% moisture.
Both A. auricula-judae and the similar A. polytricha are popular in China, where the medicinal use of food is common; a soup containing the species is used medicinally for dealing with colds and fevers by reducing the heat of the body. There is evidence that the species were being cultivated in China as early as the Tang dynasty
(618–907). Li Shih-chen, in his Pen Tsao Kang Mu, quotes Tang Ying-chuan from that period as saying "... put the steamed bran on logs, cover with straw, Wood Ear will grow". In the early 20th century, large volumes of A. auricula-judae were exported from Australia to China, and it is today still sold in Asian food shops for culinary use. It is also popular in Vietnam
, although the climate is there more suited to A. polytricha. A report on small-scale fungi cultivation concluded that A. auricula-judae would be suitable for cultivation only in cooler climates. According to a 2010 publication, the annual production of Auricularia species worldwide is the fourth highest among all industrially cultivated culinary and medicinal mushrooms
, and in China, the estimated output was roughly 1.655 million tonnes (based on 2003 data), most of which are A. polytricha however (which has by and large replaced A. auricula-judae in international trade).
Auricularia auricula-judae is also in cultivation elsewhere in the world, for instance, in Ghana
. In the Brong-Ahafo
and Ashanti
regions, it is grown with what is referred to as the "plastic bag method". Sawdust is packed into polypropylene
bags and then sterilised by steam for several hours. Once the sawdust has cooled, Sorghum
grain spawn
is added, and the bags are kept in moderately dark conditions. Once the sawdust is exposed to a humid environment, A. auricula-judae fruit bodies begin to grow. Elsewhere in the world, a study on the use of mushrooms by the Bini people inhabiting a remote village in southern Nigeria
found that the local inhabitants collected and ate A. auricula-judae, but that it was not one of the mushrooms they used medicinally. Collection of the mushroom for culinary use has also been documented in Nepal
. However, the Nepalese do not consider it a choice mushroom for eating; of the three grades given to edible mushrooms, it was given the worst. Again, unlike other mushrooms, no medicinal use was reported. The mushroom has also been the only non-morel
species exported from Nepal for culinary use. Other places where A. auricula-judae has been recorded as commonly consumed include Poland
, Mozambique
and Indonesia
, while, in Bolivia
, Goeldi's monkeys
have been recorded as commonly eating the sporocarps.
s. It was used as a poultice
to treat inflammations of the eye, as well as a palliative for throat problems. The 16th century herbalist John Gerard
, writing in 1597, recommended A. auricula-judae for a very specific use; other fungi were used more generally. He recommends the preparation of a liquid extract by boiling the fruit bodies in milk, or else leaving them steeped in beer, which would then be sipped slowly in order to cure a sore throat. The resultant broth was probably not dissimilar to the Chinese soups which utilise A. polytricha. Carolus Clusius, writing in 1601, also said that the species could be gargled to cure a sore throat, and John Parkinson
, writing in 1640, reported that boiling in milk or steeping in vinegar was "the onely use the are put unto that I know". Writing in 1694, herbalist John Pechey described A. auricula-judae by saying "It grows to the Trunk of the Elder-Tree. Being dried it will keep a good year. Boyl'd in Milk, or infus'd in Vinegarm 'tis good to gargle the Mouth or Throat in Quinsies, and other inflammations of the Mouth and Throat. And being infus'd in some proper Water, it is good in Diseases of the Eyes." The species also saw use as an astringent
due to its ability to absorb water. There are recorded medicinal usages from Scotland, where it was again used as a gargle for sore throats, and from Ireland, where, in an attempt to cure jaundice
, it was boiled in milk. The medicinal use of A. auricula-judae continued until at least 1860, when it was still sold at Covent Garden
; at the time, it was not considered edible in the United Kingdom.
Medicinal use in Indonesia
was also recorded in the 1930s, and was more recently reported in modern-day Ghana
. A report for the 2005 Commonwealth Forestry Conference examining the possible effects of deforestation in southern Ghana on medicinal and edible fungi found that A. auricula-judae was in use as a blood tonic.
s isolated from the species showed potent antitumour properties when used on mice artificially implanted with Sarcoma
180 tumours. This was despite the conclusion of earlier research indicating that, while aqueous extracts from several other fungal species had antitumour effects, extracts from A. auricula-judae did not. Further, research on genetically diabetic mice showed that a polysaccharide
extracted from A. auricula-judae had a hypoglycemic effect; mice fed with food including the polysaccharide showed reduced plasma glucose, insulin
, urinary
glucose and food intake. Another chemical extracted from the species was an acid
ic polysaccharide
(made up of mostly mannose
, glucose
, glucuronic acid
and xylose
) which showed anticoagulant
properties. The article concluded that "the polysaccharides from these mushrooms may constitute a new source of compounds with action on coagulation, platelet aggregation and, perhaps, on thrombosis". Another study reported that the species may be effective in stopping platelet
binding in vitro
, with possible uses regarding hypercholesterolemia
. Research has shown that A. auricula-judae can be used to lower cholesterol
levels generally, and, in particular, is one of two fungi shown to reduce the level of bad cholesterol.
's play The Jew of Malta
. Iathamore proclaims: "The hat he wears, Judas left under the elder when he hanged himself". Later, the species was probably partially the inspiration for Emily Dickinson
's poem beginning "The Mushroom is the Elf of Plants", which depicts a mushroom as the "ultimate betrayer". Dickinson had both a religious and naturalistic background, and so it is more than likely that she knew of the common name of A. auricula-judae, and of the folklore surrounding Judas's suicide.
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
s, is a species of edible Auriculariales
Auriculariales
The Auriculariales are an order of fungi in the class Agaricomycetes. Species within the order were formerly referred to the "heterobasidiomycetes" or "jelly fungi", since many have gelatinous basidiocarps that produce spores on septate basidia...
fungus found worldwide. The fruiting body
Basidiocarp
In fungi, a basidiocarp, basidiome or basidioma , is the sporocarp of a basidiomycete, the multicellular structure on which the spore-producing hymenium is borne. Basidiocarps are characteristic of the hymenomycetes; rusts and smuts do not produce such structures...
is distinguished by its noticeably ear-like shape and brown colouration; it grows upon wood, especially elder. Its specific epithet is derived from the belief that Judas Iscariot
Judas Iscariot
Judas Iscariot was, according to the New Testament, one of the twelve disciples of Jesus. He is best known for his betrayal of Jesus to the hands of the chief priests for 30 pieces of silver.-Etymology:...
hanged himself from an elder tree; the common name "Judas's ear" eventually became "Jew's ear", while today "jelly ear" or other names are sometimes used. The mushroom can be found throughout the year in temperate regions worldwide, where it grows upon both dead and living wood. Although it is not regarded as a choice edible mushroom
Edible mushroom
Edible mushrooms are the fleshy and edible fruiting bodies of several species of fungi. Mushrooms belong to the macrofungi, because their fruiting structures are large enough to be seen with the naked eye. They can appear either below ground or above ground where they may be picked by hand...
in the west, it has long been popular in China, to the extent that Australia exported large volumes of the mushroom to China in the early twentieth century.
While not widely consumed in the west, A. auricula-judae was used in folk medicine as recently as the 19th century for complaints including sore throats, sore eyes and jaundice
Jaundice
Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...
, and as an astringent
Astringent
An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...
. Today, the mushroom is still used for medicinal purposes in China, where soups featuring it are used as a remedy for colds; it is also used in Ghana, as a blood tonic. Modern research into possible medical applications have variously concluded that A. auricula-judae has antitumour, hypoglycemic, anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
and cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
-lowering properties.
Taxonomy and naming
The species was first mentioned in the scientific literature as Tremella auricula by Carl Linnaeus in his 1753 Species PlantarumSpecies Plantarum
Species Plantarum was first published in 1753, as a two-volume work by Carl Linnaeus. Its prime importance is perhaps that it is the primary starting point of plant nomenclature as it exists today. This means that the first names to be considered validly published in botany are those that appear...
, and later (1789) described by Jean Baptiste François Pierre Bulliard
Jean Baptiste François Pierre Bulliard
Jean Baptiste François Pierre Bulliard was a French physician and botanist....
as Tremella auricula-judae. However, the genus Tremella
Tremella
Tremella is a genus of fungi in the family Tremellaceae. All Tremella species are parasites of other fungi and most produce anamorphic yeast states. Basidiocarps , when produced, are gelatinous and are colloquially classed among the "jelly fungi". Over 100 species of Tremella are currently...
is now reserved for fungal species that live as parasites
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
on other fungi. Tremella auricula-judae is now considered a basionym
Basionym
Basionym is a term used in botany, regulated by the International Code of Botanical Nomenclature...
. In 1791, Bulliard transferred the species to the genus Peziza
Peziza
Peziza is a large genus of saprophytic cup fungi that grow on the ground, rotting wood, or dung. Most members of this genus are of unknown edibility and are difficult to identify as separate species without use of microscopy...
. In 1822, Elias Magnus Fries
Elias Magnus Fries
-External links:*, Authors of fungal names, Mushroom, the Journal of Wild Mushrooming.*...
transferred the species to Exidia
Exidia
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...
, and, in so doing, sanctioned the name
Sanctioned name
In mycology, a sanctioned name is a name that was adopted in certain works of Christiaan Hendrik Persoon or Elias Magnus Fries, which are considered major points in fungal taxonomy.-Definition and effects:...
. In 1860, Miles Joseph Berkeley
Miles Joseph Berkeley
Miles Joseph Berkeley was an English cryptogamist and clergyman, and one of the founders of the science of plant pathology....
described the species as a member of Hirneola, a genus described by Fries in 1848, now considered synonymous with Auricularia. The species was given the name Auricularia auricula-judae in 1888 by Joseph Schröter
Joseph Schröter
Joseph Schröter was a noted German mycologist, doctor and scientist. During his lifetime, he wrote several books and texts, and discovered and described many species of flora and fungi...
. The specific name of A. auricula-judae comprises auricula, the Latin word meaning ear, and Judae, meaning of Judas. Under binomial nomenclature
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
, a species name can comprise only two words; but the taxonomists responsible for this naming hyphenated the specific name to "bend the rules" and keep the name "within the letter of the law". The name was criticised by mycologist Curtis Gates Lloyd
Curtis Gates Lloyd
Curtis Gates Lloyd was an American mycologist known for both his research on the Gasteromycetes, as well as his controversial views on naming conventions in taxonomy. He had a herbarium with over 59,000 fungal specimens, and published over a thousand new species of fungi...
, who said "Auricularia auricula-Judae is cumbersome and in addition is a slander on the Jews". Though critical of Lucien Marcus Underwood
Lucien Marcus Underwood
Lucien Marcus Underwood was an American botanist and mycologist of the 19th and early 20th centuries.-Biography:He was born in New Woodstock, New York, and graduated from Syracuse University...
, saying he "would probably not have known the Jew's ear from the calves' liver", he followed him in using Auricularia auricula, which was in turn used by Bernard Lowy in an article on the entire genus. Despite this, Auricularia auricula-judae is the currently recognised name for the species by many sources, though Auricularia auricula is still occasionally used. As well as the obligate synonyms from Bulliard, Fries and Berkeley, there are numerous other synonymous names
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
. Mycologist George Willard Martin
George Willard Martin
George Willard Martin was an American mycologist. He was born in Brooklyn, New York, and received a Bachelor of Literature degree in 1912, and a Master of Science degree in 1915, both from Rutgers University...
, writing in 1943, noted that the species was known by at least 12 binomials
Binomial nomenclature
Binomial nomenclature is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin grammatical forms, although they can be based on words from other languages...
, of which none appeared to be valid, and noted that "the citations given for the various names are extremely erratic". Mycologist Mary F. Barrett attributes "such multiplication of names" to "the wide distribution of the Judas' ear, its ability to grow upon many different kinds of decaying wood, and to its great variation in size, colour and shape".
The fungus is associated with Judas Iscariot
Judas Iscariot
Judas Iscariot was, according to the New Testament, one of the twelve disciples of Jesus. He is best known for his betrayal of Jesus to the hands of the chief priests for 30 pieces of silver.-Etymology:...
because of the belief that he hanged himself on an elder tree after his betrayal of Jesus Christ. Folklore suggests that the ears are Judas's returned spirit, and are all that are left to remind us of his suicide. The common name
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
of the fungus was originally Judas's ear, but this was later shortened to Judas ear and, in the late 19th century, shortened again to Jew's ear. Common names for the fungus which refer to Judas can be traced back to at least the end of the 16th century; for instance, in the 17th century, Thomas Browne
Thomas Browne
Sir Thomas Browne was an English author of varied works which reveal his wide learning in diverse fields including medicine, religion, science and the esoteric....
wrote of the species:
In Jews' ears something is conceived extraordinary from the name, which is in propriety but fungus sambucinus, or an excrescence about the roots of elder, and concerneth not the nation of the Jews, but Judas Iscariot, upon a conceit he hanged on this tree; and is become a famous medicine in quinsies, sore throats, and strangulations, ever since.
While the term Jew's meat was a deprecatory term used for all fungi in the Middle Ages, the term is unrelated to the name Jew's ear. A further change of name to jelly ear was recommended in the List of Recommended Names for Fungi. The idea was rejected by mycologist Patrick Harding who considered it "to be the result of political correctness where it is not necessary", and who "will continue to call [the species] Jew's ear", explaining that, while anti-Semitism was commonplace in Britain, the name Jew's ear is in reference to Judas, who was a Jew. However, the name has been adopted in some recent field guide
Field guide
A field guide is a book designed to help the reader identify wildlife or other objects of natural occurrence . It is generally designed to be brought into the 'field' or local area where such objects exist to help distinguish between similar objects...
s. Unrelated common names include the ear fungus, common ear fungus, the Chinese Fungus, the pig's ear, the wood ear, the black wood ear, the tree ear and Kikurage. The species was known as "fungus sambuca" among herbalists, in reference to Sambuca, the generic name for elder.
Description
The fruit bodySporocarp (fungi)
In fungi, the sporocarp is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne...
of A. auricula-judae is normally 3 to 8 cm (1.2 to 3.1 in) across, but can be as much as 12 centimetres (4.7 in). It is distinctively shaped, typically being reminiscent of a floppy ear, though the fruit bodies can also be cup-shaped. It is normally attached to the substrate
Substrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
by the back surface of the cup, though there can also be a rudimentary stem. The species has a tough, gelatinous, elastic texture when fresh, but it dries hard and brittle. The outer surface is a bright reddish-tan-brown with a purplish hint, often covered in tiny, downy hairs of a grey colour. It can be smooth, as is typical of younger specimens, or undulating with folds and wrinkles. The colour becomes darker with age. The inner surface is a lighter grey-brown in colour and smooth. It is sometimes wrinkled, again with folds and wrinkles, and may have "veins", making it appear even more ear-like.
Microscopic features
The spores of A. auricula-judae are long and sausage shaped, ranging in size from 16 to 18 micrometres (μm) long by 6 to 8 μm thick. The spores themselves are white, cream or yellowish, and are hyalineHyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
. The spores can sometimes be seen in a whitish mass on the underside of the fruit body. The species has elongated cylindrical basidia with three transverse septa (internal cross-walls dividing the hyphae). Hairs on the fruit body are from 85 to 100 μm in length, and 5 to 6 μm in diametre. They are hyaline
Hyaline
The term hyaline denotes a substance with a glass-like appearance.-Histopathology:In histopathological medical usage, a hyaline substance appears glassy and pink after being stained with haematoxylin and eosin — usually it is an acellular, proteinaceous material...
, lack a central strand and have rounded tips. They do not grow in dense tufts.
Similar species
Auricularia auricula-judae is similar to A. fuscosuccinea in colour and texture, and "may be confused with it if only external features are considered". The spore and basidia sizes of the two species are slightly different, but this is not a reliable way to tell them apart. A. cornea is another similar species in the same genus, but has distinct internal differences, is normally more pilose (more covered in soft hair) and tends to fruit in larger numbers.Habitat, ecology and distribution
Deciduous
Deciduous means "falling off at maturity" or "tending to fall off", and is typically used in reference to trees or shrubs that lose their leaves seasonally, and to the shedding of other plant structures such as petals after flowering or fruit when ripe...
trees and shrubs, favouring elder. In up to 90% of cases, the mushroom is found on elder, but it is often incorrectly assumed to grow exclusively on elder. It has also been recorded on Acer pseudoplatanus (known in the United Kingdom as sycamore), beech
Beech
Beech is a genus of ten species of deciduous trees in the family Fagaceae, native to temperate Europe, Asia and North America.-Habit:...
, ash, spindle
Euonymus
Euonymus , often called spindle or spindle tree, is a genus of flowering plants in the staff vine family, Celastraceae. It comprises about 170–180 species of deciduous and evergreen shrubs and small trees...
, and in one particular case, the sycamore draining board of an old sink in Hatton Garden
Hatton Garden
Hatton Garden is a street and area near Holborn in London, England. It is most famous for being London’s jewellery quarter and centre of the UK diamond trade, but the area is also now home to a diverse range of media and creative businesses....
. In Australia, it is found in Eucalyptus
Eucalyptus
Eucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
woodland and rainforests; in the rainforests, it can grow in very large colonies on fallen logs. It favours older branches, where it feeds as a saprophyte (on dead wood) or a weak parasite
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
(on living wood), and it causes white rot.
Commonly growing solitarily, it can also be gregarious (in a group) or caespitose (in a tuft). Spores are ejected from the underside of the fruit bodies with as many as several hundred thousand an hour, and the high rate continues when the bodies have been significantly dried. Even when they have lost some 90% of their weight through dehydration, the bodies continue to release a small number of spores. It is found all year, but is most common in autumn. It is widespread throughout temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...
and sub-tropical
Subtropics
The subtropics are the geographical and climatical zone of the Earth immediately north and south of the tropical zone, which is bounded by the Tropic of Cancer and the Tropic of Capricorn, at latitudes 23.5°N and 23.5°S...
zones worldwide, and can be found across Europe, North America, Asia, Australia, South America and Africa. There has been some debate about the appearance of the species in the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately N and the Tropic of Capricorn in the southern hemisphere at S; these latitudes correspond to the axial tilt of the Earth...
; while it has been frequently reported there, Bernard Lowy, in an article on Auricularia, said that "of the specimens I have examined, none could be assigned here".
Edibility
Auricularia auricula-judae has a soft, jelly-like texture. Though edible, it was not held in high culinary regard in the west for many years. It has been likened to "eating an Indian rubber with bones in it", while in 19th century Britain, it was said that "it has never been regarded here as an edible fungus". It has a mild flavour, and is useful for mixed mushroom recipes, but is still considered bland in the west. It can be driedDrying (food)
Drying is a method of food preservation that works by removing water from the food, which inhibits the growth of microorganisms and hinders quality decay. Drying food using sun and wind to prevent spoilage has been practised since ancient times, and was the earliest form of food curing...
and rehydrated, sometimes swelling to a very large size. Young specimens are best, but the species is not edible when raw, needing to be cooked thoroughly. The whole fruit body can be eaten, but should be thoroughly washed before cooking. Cooking can sometimes take a comparatively long time. The nutritional content of 100 g (3.5 oz) of dried fungus includes 370 kcal
Calorie
The calorie is a pre-SI metric unit of energy. It was first defined by Nicolas Clément in 1824 as a unit of heat, entering French and English dictionaries between 1841 and 1867. In most fields its use is archaic, having been replaced by the SI unit of energy, the joule...
, 10.6 g of protein, 0.2 g of fat
Fat
Fats consist of a wide group of compounds that are generally soluble in organic solvents and generally insoluble in water. Chemically, fats are triglycerides, triesters of glycerol and any of several fatty acids. Fats may be either solid or liquid at room temperature, depending on their structure...
, 65 g of carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
, 5.8 g ash
Ash (analytical chemistry)
In analytical chemistry, ashing is the process of mineralization for preconcentration of trace substances prior to chemical analysis. Ash is the name given to all non-aqueous residue that remains after a sample is burned, and consist mostly of metal oxides....
, and 0.03% mg of carotene
Carotene
The term carotene is used for several related unsaturated hydrocarbon substances having the formula C40Hx, which are synthesized by plants but cannot be made by animals. Carotene is an orange photosynthetic pigment important for photosynthesis. Carotenes are all coloured to the human eye...
. Fresh mushrooms contain about 90% moisture.
Both A. auricula-judae and the similar A. polytricha are popular in China, where the medicinal use of food is common; a soup containing the species is used medicinally for dealing with colds and fevers by reducing the heat of the body. There is evidence that the species were being cultivated in China as early as the Tang dynasty
Tang Dynasty
The Tang Dynasty was an imperial dynasty of China preceded by the Sui Dynasty and followed by the Five Dynasties and Ten Kingdoms Period. It was founded by the Li family, who seized power during the decline and collapse of the Sui Empire...
(618–907). Li Shih-chen, in his Pen Tsao Kang Mu, quotes Tang Ying-chuan from that period as saying "... put the steamed bran on logs, cover with straw, Wood Ear will grow". In the early 20th century, large volumes of A. auricula-judae were exported from Australia to China, and it is today still sold in Asian food shops for culinary use. It is also popular in Vietnam
Vietnam
Vietnam – sometimes spelled Viet Nam , officially the Socialist Republic of Vietnam – is the easternmost country on the Indochina Peninsula in Southeast Asia. It is bordered by China to the north, Laos to the northwest, Cambodia to the southwest, and the South China Sea –...
, although the climate is there more suited to A. polytricha. A report on small-scale fungi cultivation concluded that A. auricula-judae would be suitable for cultivation only in cooler climates. According to a 2010 publication, the annual production of Auricularia species worldwide is the fourth highest among all industrially cultivated culinary and medicinal mushrooms
Medicinal mushrooms
Medicinal mushrooms are mushrooms, or mushroom extracts, that are used or studied as possible treatments for diseases. Lentinula edodes , Grifola frondosa , Ganoderma lucidum , and Cordyceps, have a history of medicinal use spanning millennia in parts of Asia...
, and in China, the estimated output was roughly 1.655 million tonnes (based on 2003 data), most of which are A. polytricha however (which has by and large replaced A. auricula-judae in international trade).
Auricularia auricula-judae is also in cultivation elsewhere in the world, for instance, in Ghana
Ghana
Ghana , officially the Republic of Ghana, is a country located in West Africa. It is bordered by Côte d'Ivoire to the west, Burkina Faso to the north, Togo to the east, and the Gulf of Guinea to the south...
. In the Brong-Ahafo
Brong-Ahafo Region
The Brong-Ahafo Region is located in mid-western Ghana, between the Ashanti Region and the Northern Region. Its capital is Sunyani.This region was created in 1958. It contains many cultural and wildlife attractions, but it is less known to tourists than the Ashanti, Northern, Central, or Greater...
and Ashanti
Ashanti Region
The Ashanti Region is the third largest of 10 administrative regions in Ghana, occupying a total land surface of 24389 square kilometers or 10.2 per cent of the total land area of Ghana. In terms of population, however, it is the most populated region with a population of 3,612,950 in 2000,...
regions, it is grown with what is referred to as the "plastic bag method". Sawdust is packed into polypropylene
Polypropylene
Polypropylene , also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging, textiles , stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes...
bags and then sterilised by steam for several hours. Once the sawdust has cooled, Sorghum
Sorghum
Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...
grain spawn
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
is added, and the bags are kept in moderately dark conditions. Once the sawdust is exposed to a humid environment, A. auricula-judae fruit bodies begin to grow. Elsewhere in the world, a study on the use of mushrooms by the Bini people inhabiting a remote village in southern Nigeria
Nigeria
Nigeria , officially the Federal Republic of Nigeria, is a federal constitutional republic comprising 36 states and its Federal Capital Territory, Abuja. The country is located in West Africa and shares land borders with the Republic of Benin in the west, Chad and Cameroon in the east, and Niger in...
found that the local inhabitants collected and ate A. auricula-judae, but that it was not one of the mushrooms they used medicinally. Collection of the mushroom for culinary use has also been documented in Nepal
Nepal
Nepal , officially the Federal Democratic Republic of Nepal, is a landlocked sovereign state located in South Asia. It is located in the Himalayas and bordered to the north by the People's Republic of China, and to the south, east, and west by the Republic of India...
. However, the Nepalese do not consider it a choice mushroom for eating; of the three grades given to edible mushrooms, it was given the worst. Again, unlike other mushrooms, no medicinal use was reported. The mushroom has also been the only non-morel
Morel
Morchella, the true morels, is a genus of edible mushrooms closely related to anatomically simpler cup fungi. These distinctive mushrooms appear honeycomb-like in that the upper portion is composed of a network of ridges with pits between them....
species exported from Nepal for culinary use. Other places where A. auricula-judae has been recorded as commonly consumed include Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
, Mozambique
Mozambique
Mozambique, officially the Republic of Mozambique , is a country in southeastern Africa bordered by the Indian Ocean to the east, Tanzania to the north, Malawi and Zambia to the northwest, Zimbabwe to the west and Swaziland and South Africa to the southwest...
and Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
, while, in Bolivia
Bolivia
Bolivia officially known as Plurinational State of Bolivia , is a landlocked country in central South America. It is the poorest country in South America...
, Goeldi's monkeys
Goeldi's Marmoset
Goeldi's marmoset or Goeldi's monkey is a small, South American New World monkey that lives in the upper Amazon Basin region of Bolivia, Brazil, Colombia, Ecuador, and Peru...
have been recorded as commonly eating the sporocarps.
Folk medicine
Auricularia auricula-judae has been used as a medicinal mushroom by many herbalistHerbalist
An herbalist is:#A person whose life is dedicated to the economic or medicinal uses of plants.#One skilled in the harvesting and collection of medicinal plants ....
s. It was used as a poultice
Poultice
A poultice, also called cataplasm, is a soft moist mass, often heated and medicated, that is spread on cloth over the skin to treat an aching, inflamed, or painful part of the body. It can be used on wounds such as cuts...
to treat inflammations of the eye, as well as a palliative for throat problems. The 16th century herbalist John Gerard
John Gerard
John Gerard aka John Gerarde was an English herbalist notable for his herbal garden and botany writing. In 1597 he published a large and heavily illustrated "Herball, or Generall Historie of Plantes", which went on to be the most widely circulated botany book in English in the 17th century...
, writing in 1597, recommended A. auricula-judae for a very specific use; other fungi were used more generally. He recommends the preparation of a liquid extract by boiling the fruit bodies in milk, or else leaving them steeped in beer, which would then be sipped slowly in order to cure a sore throat. The resultant broth was probably not dissimilar to the Chinese soups which utilise A. polytricha. Carolus Clusius, writing in 1601, also said that the species could be gargled to cure a sore throat, and John Parkinson
John Parkinson (botanist)
John Parkinson was the last of the great English herbalists and one of the first of the great English botanists. He was apothecary to James I and a founding member of the Worshipful Society of Apothecaries in December 1617, and was later Royal Botanist to Charles I...
, writing in 1640, reported that boiling in milk or steeping in vinegar was "the onely use the are put unto that I know". Writing in 1694, herbalist John Pechey described A. auricula-judae by saying "It grows to the Trunk of the Elder-Tree. Being dried it will keep a good year. Boyl'd in Milk, or infus'd in Vinegarm 'tis good to gargle the Mouth or Throat in Quinsies, and other inflammations of the Mouth and Throat. And being infus'd in some proper Water, it is good in Diseases of the Eyes." The species also saw use as an astringent
Astringent
An astringent substance is a chemical compound that tends to shrink or constrict body tissues, usually locally after topical medicinal application. The word "astringent" derives from Latin adstringere, meaning "to bind fast"...
due to its ability to absorb water. There are recorded medicinal usages from Scotland, where it was again used as a gargle for sore throats, and from Ireland, where, in an attempt to cure jaundice
Jaundice
Jaundice is a yellowish pigmentation of the skin, the conjunctival membranes over the sclerae , and other mucous membranes caused by hyperbilirubinemia . This hyperbilirubinemia subsequently causes increased levels of bilirubin in the extracellular fluid...
, it was boiled in milk. The medicinal use of A. auricula-judae continued until at least 1860, when it was still sold at Covent Garden
Covent Garden
Covent Garden is a district in London on the eastern fringes of the West End, between St. Martin's Lane and Drury Lane. It is associated with the former fruit and vegetable market in the central square, now a popular shopping and tourist site, and the Royal Opera House, which is also known as...
; at the time, it was not considered edible in the United Kingdom.
Medicinal use in Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
was also recorded in the 1930s, and was more recently reported in modern-day Ghana
Ghana
Ghana , officially the Republic of Ghana, is a country located in West Africa. It is bordered by Côte d'Ivoire to the west, Burkina Faso to the north, Togo to the east, and the Gulf of Guinea to the south...
. A report for the 2005 Commonwealth Forestry Conference examining the possible effects of deforestation in southern Ghana on medicinal and edible fungi found that A. auricula-judae was in use as a blood tonic.
Pharmacology
Auricularia auricula-judae has been the subject of research into possible medicinal applications. Experiments in the 1980s concluded that two glucanGlucan
A glucan molecule is a polysaccharide of D-glucose monomers linked by glycosidic bonds.Many beta-glucans are medically important.-Types:The following are glucans:-Alpha:...
s isolated from the species showed potent antitumour properties when used on mice artificially implanted with Sarcoma
Sarcoma
A sarcoma is a cancer that arises from transformed cells in one of a number of tissues that develop from embryonic mesoderm. Thus, sarcomas include tumors of bone, cartilage, fat, muscle, vascular, and hematopoietic tissues...
180 tumours. This was despite the conclusion of earlier research indicating that, while aqueous extracts from several other fungal species had antitumour effects, extracts from A. auricula-judae did not. Further, research on genetically diabetic mice showed that a polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
extracted from A. auricula-judae had a hypoglycemic effect; mice fed with food including the polysaccharide showed reduced plasma glucose, insulin
Insulin
Insulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
, urinary
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
glucose and food intake. Another chemical extracted from the species was an acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
ic polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...
(made up of mostly mannose
Mannose
Mannose is a sugar monomer of the aldohexose series of carbohydrates. Mannose is a C-2 epimer of glucose. It is not part of human metabolism, but is a component of microbial cell walls, and is therefore a target of the immune system and also of antibiotics....
, glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
, glucuronic acid
Glucuronic acid
Glucuronic acid is a carboxylic acid. Its structure is similar to that of glucose. However, glucuronic acid's sixth carbon is oxidized to a carboxylic acid...
and xylose
Xylose
Xylose is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional group. It is the precursor to hemicellulose, one of the main constituents of biomass...
) which showed anticoagulant
Anticoagulant
An anticoagulant is a substance that prevents coagulation of blood. A group of pharmaceuticals called anticoagulants can be used in vivo as a medication for thrombotic disorders. Some anticoagulants are used in medical equipment, such as test tubes, blood transfusion bags, and renal dialysis...
properties. The article concluded that "the polysaccharides from these mushrooms may constitute a new source of compounds with action on coagulation, platelet aggregation and, perhaps, on thrombosis". Another study reported that the species may be effective in stopping platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days...
binding in vitro
In vitro
In vitro refers to studies in experimental biology that are conducted using components of an organism that have been isolated from their usual biological context in order to permit a more detailed or more convenient analysis than can be done with whole organisms. Colloquially, these experiments...
, with possible uses regarding hypercholesterolemia
Hypercholesterolemia
Hypercholesterolemia is the presence of high levels of cholesterol in the blood. It is not a disease but a metabolic derangement that can be caused by many diseases, notably cardiovascular disease...
. Research has shown that A. auricula-judae can be used to lower cholesterol
Cholesterol
Cholesterol is a complex isoprenoid. Specifically, it is a waxy steroid of fat that is produced in the liver or intestines. It is used to produce hormones and cell membranes and is transported in the blood plasma of all mammals. It is an essential structural component of mammalian cell membranes...
levels generally, and, in particular, is one of two fungi shown to reduce the level of bad cholesterol.
Cultural depictions
The species is referred to in Christopher MarloweChristopher Marlowe
Christopher Marlowe was an English dramatist, poet and translator of the Elizabethan era. As the foremost Elizabethan tragedian, next to William Shakespeare, he is known for his blank verse, his overreaching protagonists, and his mysterious death.A warrant was issued for Marlowe's arrest on 18 May...
's play The Jew of Malta
The Jew of Malta
The Jew of Malta is a play by Christopher Marlowe, probably written in 1589 or 1590. Its plot is an original story of religious conflict, intrigue, and revenge, set against a backdrop of the struggle for supremacy between Spain and the Ottoman Empire in the Mediterranean that takes place on the...
. Iathamore proclaims: "The hat he wears, Judas left under the elder when he hanged himself". Later, the species was probably partially the inspiration for Emily Dickinson
Emily Dickinson
Emily Elizabeth Dickinson was an American poet. Born in Amherst, Massachusetts, to a successful family with strong community ties, she lived a mostly introverted and reclusive life...
's poem beginning "The Mushroom is the Elf of Plants", which depicts a mushroom as the "ultimate betrayer". Dickinson had both a religious and naturalistic background, and so it is more than likely that she knew of the common name of A. auricula-judae, and of the folklore surrounding Judas's suicide.