Ascomycetes include pigmented moulds, powdery mildews, yeasts, cup fungi, morels and truffles. They have septate hyphae with cell wall containing
chitin or fungal cellulose. Nutritionally they are saprophytic, decomposers, parasitic or coprophilous. Asexual reproduction occurs by budding, fission, oidia stage and through exogenously produced conidia. Sexual reproduction takes place by gametic fusion, gametangial contact and autogamy. Ascus (sac) a sporangial sac peculiar to Ascomycetes is formed and hence the group is also called sac fungi.