(1889) Mitruliopsis flavida Peck (1903) Spathularia flavida, commonly known as the yellow earth tongue, the yellow fan, or the fairy fan, is an ascomycete fungus found in coniferous forests of Asia, Europe and North America.

Schaeffer gave it the binomial Elvella clavata, and called it Der keulenförmige Faltenschwamm ("the club-shaped wrinkled sponge") in the vernacular.

[5] According to the taxonomical database MycoBank,[1] additional synonyms include Boletus elvela as defined by August Johann Georg Karl Batsch in 1783, and Spathularia clavata published by Pier Andrea Saccardo in 1889.

The paraphyses (sterile cells found in the hymenium) are filamentous, and hyaline (translucent); some are ring-shaped (circinate).

[13] Mains described a number of varieties of S. flavida based largely on differences in the shapes and sizes of their spores.

[2] The closely related species S. neesi has an ochre color,[18] spores that measure 60–80 by 1.5–2 μm, and paraphyses that are branched on the upper parts.

[20] Another yellowish earth-tongue fungus, Microglossum rufum, has a well-defined oval to spoon-shaped head, and sausage- to spindle-shaped spores that are 18–38 by 4–6 μm.

[23] In Europe, it has been collected from Britain,[15] Germany,[24] Spain,[25] Austria, Belgium, Scandinavia, and Italy;[26] in Asia, it has been reported from India[27] Japan,[28] and Turkey.

Thought to be a saprobic species (that is, obtaining nutrients from dead or decomposing organic matter),[17] it has also been found on rotten wood.

"[30] The fungus is able to protect itself from mycophagy by the springtail Ceratophysella denisana, a common mushroom feeder, by releasing repellent odorous compounds when it is injured.