Black Witches’ Butter

(Exidia glandulosa)

Conservation Status

IUCN Red List

not listed


NNR - Unranked


not listed

Black Witches’ Butter
Photo by Luciearl

Black Witches’ Butter is a common gelatinous fungus. It occurs worldwide on all continents except Antarctica. In the United States, it occurs east of the Great Plains and west of the Rocky Mountains.

Black Witches’ Butter fruits only in cool temperatures. It appears in the spring and in the fall. It also appears in unseasonably warm spells in the winter and cold spells in the summer. It grows on dead wood, including recently dead wood, of hardwoods, especially oaks. It is usually found on dead or dying, fallen or attached branches. It is also found on standing, dead or dying tree trunks, as shown by photos on this page. It obtains its nutrients from dead wood (saprobic).

When it first appears, the fruiting body appears like a translucent blister. As it ages, it darkens and spreads out. The mature fruiting body is black, shiny, to ¾ (1 to 2 cm) in diameter, blister-like or cushion-like, and depressed in the middle, “like an inverted cone” (Wikipedia). It is attached directly to the substrate, without a stalk. The upper surface, which is the fertile surface, may be smooth or rough, dotted with warts. The warts are minute, and it may require a hand lens to see them. Fruiting bodies may appear singly or in small clusters, but they do not fuse into large or long sheets. When older specimens dry out, they form a flat, black crust.

The flesh is gelatinous and insignificant. The edibility is unknown and is likely to remain so.

The spore print is white.


Similar Species

Warlock’s Butter (Exidia nigricans)

Habitat and Hosts

Hardwoods, especially oaks



Spring and fall


Distribution Map



4, 24, 26, 29, 30, 77.

Black Witches’ Butter is very similar to, often confused with, and often lumped together with Warlock’s Butter (Exidia nigricans). For this reason, the exact distribution of each species is uncertain. Both species occur in Minnesota.



Common and widespread



Fungi (fungi)




Basidiomycota (club fungi)


Agaricomycotina (jelly fungi, yeasts, and mushrooms)


Agaricomycetes (mushrooms, bracket fungi, puffballs, and allies)










This species was originally described as Tremella glandulosa in 1789. In 1822, it was moved to the genus Exidia and lumped with a similar species under the name Exidia glandulosa. In 1936, the two species were separated. This species became Exidia truncata and the other species retained the name Exidia glandulosa, but this was an error. In 1966 the error was corrected, and this species regained its original name, Exidia glandulosa. The other species became Exidia plana, but the name was later changed to Exidia nigricans. Recent molecular research (Weiss, 2001) confirms the separation of the species.

The two species are still usually lumped together in both print and online sources.



Subordinate Taxa

Two subspecies and four varieties have been described, but these are not generally recognized.



Auricularia glandulosa

Exidia duthieae

Exidia duthiei

Exidia purpureocinerea

Exidia truncata

Peziza glandulosa

Spicularia glandulosa

Tremella arborea

Tremella atra

Tremella glandulosa

Tremella nigricans var. glandulosa

Tremella spiculosa


Common Names

Black Jelly Roll

Black Witches’ Butter

Black Witche’s Butter

Warty Jelly Fungus

Witches’ Butter











A term often used for saprotrophic fungi. Referring to fungi that obtain their nutrients from decayed organic matter.






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Other Videos

Wortcunning: Black Witches Butter {Exidia glandulosa}
Scott Riddle


Jan 18, 2017

Exidia glandulosa - often referred to as Black Witch's (or Witches') Butter, perhaps because of its butter-like consistency and greasy surface when wet as well as its sombre colour, occurs throughout the year on dead hardwood.

An alternative theory for the origin of the common name of this fairly common jelly fungus is that this species was thought to have the power to counteract witchcraft if the fruit-bodies were thrown on to a blazing fire - probably not instead of the witches, I fear!

Jelly fungi have been used for medicinal purposes in Asia for millennia as a means to improve breathing and circulation; extended longevity is widely attributed to the consumption of tremelloid fungi over a long period of time. Investigation of the medicinal benefits of the jelly fungi in general and T. fuciformis in particular has revealed that they stimulate the immune system, reduce inflammation, lower cholesterol and are useful in the treatment of allergies and diabetes. A group of Israeli and Ukrainian researchers evaluated fungi of the Tremella genus in 2000 and confirmed that they exhibited antitumor properties and that they could be used to "improve immunodeficiency … and to prevent senile degeneration of microvessels." They attributed these effects to the presence of long chain sugars called polysaccharides, notably the acidic heteropolysacharide glucoronoxylomannan.

Exidia glandulosa - IV, March 2020
Грибы БАК - Mushrooms of the LHC


Mar 6, 2020

Эксидия железистая - IV, 6 марта 2020 года

Google Translate: Exidia glandularis - IV, March 6, 2020



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Location: Fairview Twp.

Black Witches’ Butter


Location: Fairview Twp.

Black Witches’ Butter Sightings






Created: 2/16/2024

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