T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Mould (Bonnet mould) Spinellus fusiger

Kingdom: Fungi
Division: Zygomycota
Class: Zygomycetes
Order: Mucorales (Pin moulds).
Family: Phycomycetaceae
Genus: Spinellus
Species: S. fusiger
Binomial name: Spinellus fusiger
Synonyms: Mucor rhombosporus, Mucor fusiger, Mucor macrocarpus, Spinellus macrocarpus, Spinellus rhombosporus, Phycomyces agaricicola.
Common names: Bonnet mould, Mycena pin mould.

Spinellus fusiger is a widely distributed fungi that usually grows by parasitising several agarics (mushrooms), but species of Mycena seem to be the preferred hosts.
The hyphae of these fungi, unlike those of ascomycetes or basidiomycetes, they are septate, which means they have no barriers to slow the movement of cytoplasm, allowing them to grow extremely quickly.
Spinellus fusiger produces radiating reproductive stalks (sporangiophores) bearing globose terminal sporangia (spore-containing structures). When mature the sporangia turn black and the asexual spores are released by the breakdown of the outer sporangial wall and hundreds are then passively dispersed by wind, water, insects etc. to new sites.

Video of the life history of a pin mould. This study of pin mould is aided by diagrammatic, time-lapse, and microscopic footage.  https://www.youtube.com/embed/nrHudktMYB0

Spinellus fusiger (Bonnet Mould) on a Mycena mushroom. Click to enlarge.

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/