Such fungi do not have sexual stages, they are named as imperfect fungi.
The asexual reproduction takes place only by fragmentation, budding or conidiospores.
They plays an important role in facilitating the decomposition of organic matter, replenishing the nutrient content, and used for pharmaceutical products.
Deuteromycetes: Deuteromycetes is a class of fungi which lacks sexual mode of reproduction and hence named as imperfect fungi. Example : Alternaria, Colletotrichum, Trichoderma etc.