As a result, they advocate for continued use of Singer's concept of Marasmiellus until the taxonomic relationships are more definitively resolved.

[4] Species of Collybiopsis have a diverse range of fruiting body forms, including shapes reminiscent of the genera Collybia, Gymnopus, Marasmiellus, Omphalina, and Pleurotus.

The stipe can be centrally or eccentrically positioned and may grow directly from the substrate (insititious) or have a slightly wider base (subinsititious).

Microscopically, Collybiopsis is characterised by ellipsoid to oblong spores that are transparent (hyaline) and do not react with iodine stain (inamyloid).

The cap's outer layer (pileipellis) is distinguished by coral-like or branching (diverticulate) structures at the tips of its fungal filaments.