The perfect (sexual) stage not seen in

The perfect (sexual) stage is not seen in Deuteromycotina.
The fungi imperfecti or imperfect fungi are fungi that do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures.
They are known as imperfect fungi because only their asexual and vegetative phases are known. They have an asexual form of reproduction, meaning that these fungi produce their spores asexually, in a process called sporogenesis.