Cystidium

Cystidium is a term that can refer to different structures in various branches of biology, including botany and zoology. However, it is most commonly associated with the field of mycology, where it denotes a specific type of structure found in certain fungi. This article will focus on the cystidium as it pertains to mycology, while also providing brief insights into its meaning in other contexts.

Definition

In mycology, a cystidium (plural: cystidia) is a sterile cell found on the gills or other spore-bearing surfaces of some fungi. Unlike basidia, which are spore-producing cells, cystidia do not play a direct role in reproduction. Instead, they are thought to serve various functions such as preventing the drying out of the spore-bearing surface, releasing substances that deter grazing by small animals, or playing a role in the dispersal of spores.

Types of Cystidia

Cystidia can vary greatly in shape, size, and location, leading to their classification into several types:

• Cheilocystidia: Found on the gill edges (cheilo- meaning "lip").
• Pleurocystidia: Located on the gill faces (pleuro- meaning "side").
• Lamprocystidia: Characterized by their thick walls and often bright contents.
• Metuloids: A type of cystidia that is particularly thick-walled and often has a distinct shape.

Function

The exact function of cystidia is still a subject of research, but they are believed to contribute to the overall health and survival of the fungus. By maintaining moisture on the spore-bearing surfaces, they help in the efficient dispersal of spores. The substances they release may also protect the fungus from predation and microbial attack.

Cystidium in Other Contexts

In botany, a cystidium refers to a bladder-like structure in certain algae and lichens, serving different functions such as storage or protection. In zoology, the term can describe a type of cell or structure in various animals, often related to the excretory or reproductive systems.

Research and Importance

Studying cystidia is important for mycologists, especially in the identification and classification of fungi. The presence, absence, and type of cystidia are key characteristics used to differentiate between closely related species.

See Also

• Mycology
• Fungus
• Spore
• Basidium