What is "basidium"

Basidium \Ba*sid"i*um\, n. [NL., dim. of Gr. ba`sis base.] (Bot.) A special oblong or pyriform cell, with slender branches, which bears the spores in that division of fungi called Basidiomycetes, of which the common mushroom is an example.

n. (context mycology English) A small structure, shaped like a club, found in the Basidiomycota division of fungi, that bears four spores at the tips of small projections.

1. n. a small club-shaped structure typically bearing four basidiospores at the ends of minute projections; unique to basidiomycetes

2. [also: basidia (pl)]

thumb|right|500px|Schematic showing a basidiomycete mushroom, gill structure, and spore-bearing basidia on the gill margins. A basidium (pl., basidia) is a microscopic, spore-producing structure found on the hymenophore of fruiting bodies of basidiomycete fungi. The presence of basidia is one of the main characteristic features of the Basidiomycota. A basidium usually bears four sexual spores called basidiospores; occasionally the number may be two or even eight. In a typical basidium, each basidiospore is borne at the tip of a narrow prong or horn called a sterigma (pl. sterigmata), and is forcibly discharged upon maturity.

The word basidium literally means little pedestal, from the way in which the basidium supports the spores. However, some biologists suggest that the structure more closely resembles a club. An immature basidium is known as a basidiole.