Wood Ear (Auricularia)
2023 nomenclatural proposal
In 2023, mycologists formally proposed replacing 'Auricularia auricula-judae' with 'Auricularia auricula' to conserve the older, less culturally loaded scientific name — a proposal decades in the making.
Autumn et al., F1000Research, 2023
1646
Thomas Browne noted 'Jew's ear' was a mistranslation of 'Judas ear'
2 species
A. auricula-judae (wood ear) and A. polytricha (cloud ear) sold interchangeably
6+ names
wood ear, black fungus, jelly ear, cloud ear, Mu Er, Kikurage — one mushroom
Autumn et al., F1000Research, 2023
View as image ↗Few foods have a naming history as strange as this mushroom. In medieval Europe it was called Judas ear — because according to legend, Judas Iscariot hanged himself from an elder tree (Sambucus nigra), which is one of the fungus's preferred hosts, and the ear-shaped fruiting bodies that grew from elder bark were understood as his ear left behind. By the 16th century, "Judas ear" had become "Jew's ear" in English common usage — a mistranslation that the English naturalist Thomas Browne noted as an error as early as 1646, in his Pseudodoxia Epidemica (Vulgar Errors).
That mistake persisted in English for nearly four hundred years. In 2023, mycologists filed a formal proposal to the international code of botanical nomenclature to retire the scientific name Auricularia auricula-judae in favor of the older, pre-Judas name Auricularia auricula.[1]
The naming confusion does not stop with etymology. In markets across East Asia and in every grocery store in the US with an international aisle, the same mushroom is sold under "black fungus," "wood ear," "cloud ear," and "dried fungus" — labels that sometimes refer to different species and sometimes to the same one. This article disentangles the names, species, and geographic conventions. The science behind wood ear mushroom's bioactives is covered in What Is Wood Ear Mushroom? The Ancient Blood Health Mushroom.
Key Takeaways
- The name "Jew's ear" is a 16th-century English mistranslation of the medieval Latin "Judas ear" (auricula Judae), which referred to Judas Iscariot's legendary association with elder trees where the fungus grows
- Thomas Browne identified this as a translation error in 1646; the correct English form should have been "Judas ear"
- In 2023, mycologists formally proposed replacing Auricularia auricula-judae with Auricularia auricula in the international nomenclatural code (Autumn et al., F1000Research, 2023)
- "Wood ear" and "Jelly ear" (UK) refer primarily to Auricularia auricula-judae; "Cloud ear" refers to Auricularia polytricha, a smaller, thinner, tropical relative
- "Black fungus" and the Mandarin name "Mu Er" (木耳 — wood ear) are used for both species interchangeably in Chinese culinary contexts
- Auricularia polytricha polysaccharides show immune-activating properties in laboratory research, though less studied than auricula-judae (Xu et al., 2024)
From Judas to Jew's Ear: How the Name Changed Over Centuries
The elder tree (Sambucus nigra) is one of the primary hosts for Auricularia auricula-judae in temperate Europe. In medieval Christian tradition, Judas Iscariot — the apostle who betrayed Jesus — was believed to have hanged himself from an elder tree. The fungal ear-shaped growths on elder bark became associated with this legend. The Latin name auricula Judae (Judas's ear) appears in medieval botanical manuscripts as the standard term for the fungus.
The passage from Latin to vernacular English introduced an error. "Judas" in English became "Jew's" — a contraction or mishearing that changed the referent entirely. By the 16th century, English texts referred to the fungus as "Jew's ear" rather than "Judas ear," and the name became fixed in common usage through herbals and field guides.
The error was documented early. Thomas Browne, in his 1646 work Pseudodoxia Epidemica (a catalog of popular errors), noted that "Jew's ear" was a mistranslation — the fungus's name referred to Judas, not to Jewish people as a category. French retained the correct reference: the French name Oreille de Judas (Judas ear) survived without corruption. German similarly kept Judasohr (Judas ear). Only English made the shift that created the offensive common name.
In the 20th century, the UK adopted "jelly ear" as a neutral alternative, reflecting the mushroom's gelatinous texture rather than its etymology. The name "jelly ear" is now standard in British mycological literature. In the United States and across East Asia, "wood ear" became the dominant English-language term — describing the mushroom's texture and growing habit without the historical baggage.
The Scientific Name: A Nomenclatural Controversy
The scientific naming history runs parallel to the common name history, with its own complications.
Carl Linnaeus classified the fungus in 1753 as Tremella auricula — placing it in the jelly fungi genus, using the Latin word auricula (ear). Jean Baptiste François Pierre Bulliard revised this in 1789, moving it to the genus Auricularia and appending judae — producing Auricularia auricula-judae, the name that became standard in mycological literature for the next two centuries.
The problem: Bulliard's 1789 name contains the Judas reference explicitly, embedding the theological legend in the formal scientific nomenclature. And because Linnaeus's 1753 classification (Tremella auricula) predates Bulliard's by 36 years, the principle of nomenclatural priority — which gives precedence to the older name — would technically favor restoring a form closer to Linnaeus's original.
In 2023, Autumn and colleagues filed a formal proposal with the international mycological nomenclature body to conserve the name Auricularia auricula — dropping the -judae suffix and reverting to a form of the name that reflects Linnaeus's original while removing the culturally sensitive reference.[1] The proposal traced the full nomenclatural history from 1753 to the present and argued that the older, simpler name should take precedence on both historical and cultural grounds.
Whether this proposal is formally adopted determines how future scientific literature will cite the species. For now, Auricularia auricula-judae remains the standard scientific name. In supplement contexts, you may see either form — or the simpler label Auricularia auricula on products that have already made the shift.
A Comparison Table: All the Names in One Place
The following table covers the major names used for wood ear mushrooms in culinary, scientific, and regional contexts.
| Name | Species | Region / Context | Origin of the Name |
|---|---|---|---|
| Jew's ear | A. auricula-judae | Historic UK/Europe | Mistranslation of "Judas ear"; considered offensive |
| Judas ear | A. auricula-judae | Medieval Latin, modern UK mycology | Judas Iscariot legend — elder tree |
| Jelly ear | A. auricula-judae | Modern UK | Neutral: describes the gelatinous texture |
| Wood ear | A. auricula-judae | US, East Asia (English) | Describes growth on wood; ear-like shape |
| Black fungus | Both species | Chinese and Asian markets globally | Color of dried/cooked product |
| Cloud ear | A. polytricha | China, Southeast Asia, US grocers | Smaller, thinner — resembles a wispy cloud |
| Mu Er (木耳) | Both species | Mandarin Chinese | Literally: wood ear (木 = wood, 耳 = ear) |
| Yun Er (云耳) | A. polytricha | Mandarin Chinese | Cloud ear (云 = cloud) |
| Kikurage (木耳) | Both species | Japanese | Tree ear — same characters as Mu Er in Japanese reading |
| Oreille de Judas | A. auricula-judae | French | Judas ear — preserved the correct reference |
| Judasohr | A. auricula-judae | German | Judas ear — preserved the correct reference |
| Auricularia auricula-judae | A. auricula-judae | Scientific | Bulliard 1789 — under review per 2023 proposal |
Wood Ear vs. Cloud Ear vs. Black Fungus: Two Species, Many Names
"Wood ear" and "cloud ear" are not different names for the same mushroom. They refer to two different species within the genus Auricularia, which are related but distinguishable.
Auricularia auricula-judae — the true wood ear — is the larger, thicker, more heavily rippled species. It grows primarily on elder and other hardwood trees in temperate regions: Europe, North America, East Asia. It is the species with the longest research history and the most extensive pharmacological documentation. The 2024 comprehensive structure-activity review of Auricularia polysaccharides focused primarily on auricula-judae data.[3]
Auricularia polytricha — cloud ear — is smaller, thinner, and grows in tropical and subtropical regions: China, Southeast Asia, tropical Africa. When dried, it curls into tight, wispy shapes that Chinese culinary tradition likens to clouds — hence "cloud ear" (Yun Er, 云耳). Cloud ear is more common in Chinese restaurant dishes because it is cheaper to grow at scale in tropical Asia and has a slightly more delicate texture than wood ear.
A third species, Auricularia cornea, grows widely in tropical Asia and is often sold as cloud ear or black fungus. Mineral profiling of Auricularia cornea strains found iron content ranging from 26 to 41 mg per 100g dry weight across different cultivated strains — among the highest iron values measured in any edible mushroom category.[2]
Black fungus is neither species-specific nor preparation-specific. In Chinese grocery contexts it refers to the dried product of either auricula-judae or polytricha — or often both mixed together. The black appearance is more pronounced after drying and rehydration. Both species have similar culinary uses: added to soups, stir-fries, and salads after reconstitution in water.
The polysaccharide compounds responsible for wood ear's cardiovascular and immune properties are found in both species, though at different concentrations. Auricularia polytricha polysaccharides have been shown to polarize macrophages from the M2 (immunosuppressive) to the M1 (anti-tumor) phenotype in laboratory research,[4] but the evidence base for polytricha is substantially smaller than for auricula-judae. Most of the pharmacological research — including the anticoagulant mechanism, the polysaccharide-iron complex, and the hepatoprotective melanin data — is from auricula-judae specifically.
Regional Names in Their Cultural Context
The naming variation across languages reflects different aspects of the same mushroom.
In Japanese, kikurage (木耳) uses the same two characters as the Mandarin Mu Er — but with Japanese pronunciation. The characters mean "tree" (木) and "ear" (耳). In both languages the name simply describes what the mushroom looks like and where it grows, without reference to Judas, Jewish people, or any historical narrative.
In Mandarin, the word for the cloud ear (Yun Er, 云耳) distinguishes it from wood ear (Mu Er, 木耳) by referring to its cloud-like appearance when dried and curled. This distinction is consistent in Chinese culinary practice, even though both are often labeled "black fungus" in translation.
French and German mycological traditions preserved the original Judas reference — Oreille de Judas in French, Judasohr in German — avoiding the mistranslation that created the English "Jew's ear." These languages never made the error that English did, so the movement to rename is primarily an English-language concern.
In the context of Traditional Chinese Medicine, the mushroom is referred to as Hei Mu Er (黑木耳 — black wood ear) when the full dried product is used, or simply Mu Er (木耳) in everyday cooking. TCM literature records its use for over 1,000 years for blood circulation, liver health, and "cooling" the body — traditional language that maps, at least partially, to the anticoagulant and hepatoprotective activities documented in modern research.
What the Name on the Label Actually Tells You
For anyone buying wood ear mushroom as food or supplement, the naming landscape has practical consequences.
"Wood ear," "jelly ear," and Auricularia auricula-judae all refer to the same species. Products labeled with any of these terms should contain the true wood ear mushroom.
"Cloud ear," "silver ear fungus," and Auricularia polytricha refer to the smaller cloud ear species. These are used interchangeably with wood ear in cooking but have a distinct species identity and a thinner compound profile in the research literature.
"Black fungus" on a label does not specify species. It may be auricula-judae, polytricha, cornea, or a mixture. This is the least informative label for anyone interested in the specific polysaccharide fractions documented in research.
"Auricularia auricula" (without the -judae) may reflect early adoption of the 2023 nomenclatural proposal, or it may simply be an abbreviated form. Without additional species verification, it cannot be distinguished from auricula-judae based on the label alone.
For the full pharmacological profile of wood ear mushroom and its bioactive compounds, see Wood Ear Bioactive Compounds: Polysaccharides, Melanin, and Minerals. For how mushroom polysaccharides from multiple species work as gut prebiotics, see Mushroom Polysaccharides and Microbiome Nourishment.
The Bottom Line
Wood ear mushroom carries one of the most tangled naming histories in edible fungi — tracing from a medieval Judas legend, through a 16th-century English mistranslation, to a 2023 scientific proposal to retire the -judae suffix from its Latin name. The mushrooms sold as "wood ear," "cloud ear," and "black fungus" belong to related but distinct Auricularia species (auricula-judae and polytricha) with overlapping culinary uses but different compound profiles in the research literature. Understanding which species is on the label matters for anyone using these mushrooms for their documented bioactive effects.
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