heterothecal

Heterothecal is a term used in botany and mycology to describe a structure that contains two distinct types of spore-bearing organs or cells. This condition is most commonly observed in fungi, specifically in certain species of lichens and fungi that produce fruiting bodies or reproductive structures.

In lichens, heterothecal refers to the presence of both an ascoma and a pycnium within the same thallus. The ascoma is the primary fruiting body where ascospores are produced, while the pycnium is a smaller, often flask-shaped structure that produces conidia, a type of asexual spore. The co-occurrence of these two types of reproductive structures in a single lichen thallus is a characteristic of heterothecal species.

Similarly, in some fungal groups, heterothecal describes reproductive structures where different types of spores are produced. This can involve the formation of both sexual spores (like ascospores or basidiospores) and asexual spores (like conidia) within the same organism or even within the same reproductive unit. The specific arrangement and morphology of these different spore-producing elements define the heterothecal condition. Understanding whether a species is heterothecal is important for its taxonomic classification and for studying its reproductive biology.