Ascomycetes Consists of sporangial sac called ascus. Asci (singular-ascus) may occur freely or get aggregated with dikaryotic mycelium to form the fruitification called ascocarps.
The fruitification formed by asci are like
(i) Apothecium is a cup like structure, e.g., Peziza
(ii) Perithecium flask shaped, e.g., Neurospora.
(iii) Cleistothecium closed with a slit, e.g, Penicillium