Ascomycetes (Gk. askos=sac; mycete=fungus) are a large group with over 30,000 species, includes diverse types such as brown, green, blue and pink moulds, powdery mildews, yeast, morels and truffles. The mycelium is well developed and branched. The hyphae are septate and multicellular. Majority of Ascomycetes reproduce asexually by the formation of conidia. Conidia are borne on special hyphae, called conidiophores. The fructification of some Ascomycetes are edible and considered as delicacies e.g., morels, truffles. Neurospora crassa is often employed in studies conducted in experimental genetics. It is often called Drosophila of plant kingdom