Imperfect fungi, also called Deuteromycota, are classified as fungi for two main reasons. First, their multicellular tissue is quite similar to the hyphae of sac fungi and club fungi. Secondly, they have erect hyphae with asexual spores called conidiophores, similar to sac fungi and club fungi.Many imperfect fungi are related to the sac fungi because of their conidiophores closely resembling those produced by the sac fungi during their sexual phase. The imperfect fungi aren't placed in the Ascomycetes phylum because the classification of that group is completely based on the morphology of sexual structures.Under the imperfect fungi, the best known is Penicillium. Some species falling under it appear as pathogenic and are found on vegetables and fruits.