Witches’ Butter, scientifically known as Tremella mesenterica, is a distinctive and frequently encountered fungus with a bright yellow, gelatinous appearance. Often found on dead wood, its unusual form prompts questions about its nature. This article explores its characteristics, edibility, and how to distinguish it from similar fungi.
Understanding Witches’ Butter
Tremella mesenterica typically displays a vibrant yellow to orange color. Its fruit body is gelatinous, slimy, and often resembles a convoluted mass, usually measuring up to 7.5 cm (3 inches) across and 2.5 to 5 cm (1 to 2 inches) high. When dry, it shrivels into a hard, shriveled film, but it can revive its gelatinous form after subsequent rain. The fungus is commonly found on dead or decaying hardwood, particularly on barked logs and branches of deciduous trees, and it is a parasite on the mycelium of crust fungi in the genus Peniophora. It can appear year-round, often more visible after rainy periods.
Is Witches’ Butter Edible?
Tremella mesenterica is generally considered non-toxic and technically edible, though its culinary appeal is limited. It possesses a bland flavor and a gelatinous, somewhat rubbery texture.
While it offers little nutritional value, it can be used in cooking to add texture to dishes, such as soups and stews. In some Asian cultures, it is utilized in soups for its texture and perceived medicinal properties. Although some sources suggest it can be eaten raw, cooking is generally recommended to enhance palatability and aid digestion.
Avoiding Similar Species
Distinguishing Tremella mesenterica from similar-looking fungi is important for accurate identification. Tremella aurantia, often called Golden Ear, is another yellow to orange gelatinous fungus that can be confused with Witches’ Butter. Tremella aurantia primarily parasitizes Stereum hirsutum (Hairy Stereum), a different crust fungus, and its surface is often more matte and less greasy or shiny than Tremella mesenterica. Additionally, Tremella aurantia tends to have thicker lobes and retains its shape when dried, unlike Tremella mesenterica, which shrivels.
Another look-alike is Dacrymyces palmatus, also known as Orange Jelly Fungus. This species is more orange and grows exclusively on conifer wood, whereas Tremella mesenterica prefers hardwoods. Dacrymyces palmatus is also considered edible but similarly lacks distinct flavor. While Tremella mesenterica and its common look-alikes are generally not considered toxic, misidentification with other potentially harmful yellow or orange fungi remains a possibility. Therefore, it is always recommended to be absolutely certain of a mushroom’s identity before considering any wild specimen for consumption.