A fungus is initially placed in Deuteromycetes because only conidia and its vegetative mycelium are known. Its sexual st
Deuteromycetes contain fungi whose sexual stages are not known. Once a sexual stage is discovered, the fungus is moved to the class to which that stage belongs. Production of ascospores identifies the sexual form as an Ascomycete.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Fungi - Phycomycetes Ascomycetes Basidiomycetes