Editing Basidium (section)

{{Short description|Fungal structure}}
{{For|the fictional moon in novels by Eleanor Cameron|Mushroom Planet}}
{{more footnotes|date=March 2013}}
[[File:Basidium schematic.svg|thumb|right|500px|Diagram showing a basidiomycete mushroom, gill structure, and spore-bearing basidia on the gill margins.]]

A '''basidium''' ({{plural form}}: '''basidia''') is a microscopic [[spore]]-producing structure found on the [[hymenophore]] of [[sporocarp (fungi)|reproductive bodies]] of [[Basidiomycota|basidiomycete]] fungi. The presence of basidia is one of the main characteristic features of the group. These bodies are also called tertiary [[mycelium|mycelia]], which are highly coiled versions of secondary mycelia. A basidium usually bears four sexual spores called [[basidiospores]]. Occasionally the number may be two or even eight. Each reproductive spore is produced at the tip of a narrow prong or horn called a [[sterigma]] ({{plural form|sterigmata}}), and is forcefully expelled at full growth.

The word ''basidium'' literally means "little pedestal". This is the way the basidium supports the spores. However, some biologists suggest that the structure looks more like a [[club (weapon)|club]]. A partially grown basidium is known as a '''basidiole'''.