Ascus

Part of speech: noun

Definitions

1. A sac-shaped structure in fungi where spores are formed and developed
2. A specialized fungal sac that produces and contains reproductive spores
3. An enclosed spore-producing sac found in certain fungi, essential for reproduction

Etymology: The Greek word "askos" meant a leather bag or wineskin, a container for holding liquid. Ancient writers used it for the inflated hide flasks that carried wine and oil, and the same word gave English "ascus" through the scientific Latin used by naturalists. When botanists studying fungi needed a name for the tiny sac in which spores develop, they reached back to this Greek word. The resemblance was physical: each sac is a small, closed bag holding spores, much as a wineskin held its contents. The word "ascus" is therefore a New Latin coinage from classical Greek, not a term that ancient Greeks ever applied to fungi. The Greek original also survives in English as "askos," a doublet of the same word, which refers to a small ancient Greek vessel with a handle and spout. Both forms descend from one shape: a bag or vessel that holds something inside.

Synonyms: spore sac, spore case, sporangium, ascomycete sac, fungal sac