Cystidia

Cystidia are sterile cells found in fungi, particularly in the hymenium, which is the spore-bearing layer. These cells are microscopic and often have distinctive shapes and structures that are important for fungal identification. They can occur on the surface of gills, pores, or teeth, depending on the fungal group. The presence, type, and arrangement of cystidia are key characteristics used by mycologists to classify and differentiate fungal species.

There are several types of cystidia, each with a unique morphology. Cheilocystidia are found on the edges of gills, while pleurocystidia are located on the gill faces. Caulocystidia can be found on the stipe (stem) of a mushroom. Other types include lamprocystidia, which have thick walls, and metuloids, which are large, pointed cystidia that resemble the cystidia of certain rust fungi.

The function of cystidia is not fully understood, but several hypotheses exist. They may play a role in protecting the hymenium from drying out, providing mechanical support, or acting as a defense against fungivores. Some cystidia may also secrete substances that influence spore dispersal or interact with other organisms. Their detailed study is a crucial aspect of microscopic examination in mycology.