Holobasidia

Holobasidia are a type of basidium, which is the reproductive structure found in fungi belonging to the Basidiomycota phylum. The term "holobasidium" specifically refers to a basidium that is undivided by septa. This means the entire basidium is a single, unbroken cell from its base to its apex. In contrast, some basidia are septate, meaning they are divided into multiple cells by internal walls.

The holobasidium is the site where meiosis occurs, and following this process, it produces basidiospores. Typically, four basidiospores are borne on sterigmata, which are slender projections extending from the apex of the holobasidium. These spores are the primary means of asexual reproduction and dispersal for many basidiomycete fungi. The structure and development of holobasidia are key characteristics used in fungal taxonomy and identification. They are found in a wide range of basidiomycetes, including many common mushrooms. The absence of internal septa is a defining feature that distinguishes holobasidia from other types of basidia, such as phragmobasidia.