The species epithet refers to mountaineer Mavis Davidson, who collected the first known specimen of the fungus on Mount Taranaki on 17 June 1948.

[1] It has been compared with collections made by E. J. H. Corner of a Mycena rimosacuta variety alba in Borneo and found to be the same species.

It is closely related to Humidicutis lewelliniae and may merely be a white-coloured form of this species.

[6] Humidicutis mavis is a small mushroom with an umbonate cap 4–5 centimetres (1.6–2.0 inches) in diameter, initially conical and later flattening to almost flat.

[1] Fruit bodies appear singly or in groups over autumn and winter (April to July) in moss or among leaf litter in wet sclerophyll forest or rainforest in temperate, subtropical or tropical climates.