The gelatinous, orange-yellow fruit body of the fungus, which can grow up to 7.5 cm (3 in) diameter, has a convoluted or lobed surface that is greasy or slimy when damp.

It is most frequently found on both dead but attached and recently fallen branches, especially of angiosperms, as a parasite of wood decay fungi in the genus Peniophora.

This latter name is also applied to both Exidia glandulosa and Fuligo septica, and stems from Swedish and Scandinavian folklore surrounding witchcraft, in which a bile spewed up by thieving "carriers" or troll cats is referred to as, "butter of the witches.

globispora T. fuciformis T. cinnabarina T. flava T. taiwanensis T. brasiliensis T. mesenterica T. coalescens T. tropica The specific epithet is a Latin adjective formed from the Ancient Greek word μεσεντέριον (mesentérion), "middle intestine", from μεσο- (meso-, "middle, center") and ἔντερον (énteron, "intestine"), referring to its shape.

The sexual differentiation is characterized by the arrest of the growth in the G1 phase of the cell division cycle and subsequent formation of an elongated mating tube.

Asexual reproduction in T. mesenterica is carried out through the formation of spores called conidia, which arise from conidiophores—specialized hyphal cells that are morphologically distinct from the somatic hyphae.

Fruit bodies of T. aurantia contain unclamped, thick-walled host hyphae and consequently retain their shape when dried, rather than shriveling or collapsing to a film (as in T. mesenterica).

[6] Tremella mesenterica may also be confused with members of the family Dacrymycetaceae, like Dacrymyces chrysospermus (formerly D. palmatus), due to their superficial resemblance.

[20] Tremella mesenterica has a cosmopolitan distribution, having been recorded from North, Central, and South America, Africa, Europe, Asia, and Australia.

"[28] Some Tremella species produce polysaccharides that are of interest to the medical field, because of their biological activity; several patents have been filed in China pertaining to the use of these compounds for cancer prevention or immune system enhancement.

[29] In 1966, Slodki reported discovering an acidic polysaccharide from haploid cells of T. mesenterica that closely resembled those produced by the species Cryptococcus laurentii.

[32] The polysaccharide, known as glucuronoxylomannan—produced by fruit bodies and in pure culture conditions—has been shown to consist of a mannan backbone that is glycosylated with xylan chains in a regular repeating structure.

[33] Laboratory tests have associated a number of biological activities with T. mesenterica glucuronoxylomannan, including immunostimulatory, antidiabetic, anti-inflammatory, hypocholesterolemic, hepatoprotective, and antiallergic effects.