Caulocystidia

Caulocystidia are specialized sterile cells found on the stipe (stem) of certain fungi, particularly within the Agaricaceae family. They are distinct from the caulohymenium, which comprises the basidia and other fertile cells covering the stipe. Caulocystidia can vary significantly in shape, size, and arrangement, and their presence and morphology are often important taxonomic characters for identifying fungal species. They are typically clavate (club-shaped) or lageniform (flask-shaped) and can be thin-walled or thick-walled. Their function is not fully understood but is thought to be protective, aiding in spore dispersal, or possibly involved in the secretion of substances. Observing caulocystidia usually requires microscopic examination of fungal tissue. The term itself derives from the Greek words "kaulos" meaning stem and "kystis" meaning bladder or sac. Their identification and classification contribute to the broader study of fungal morphology and systematics.