A heterogeneous group of anamorphic (asexual or imperfect) fungi in which sporulation may occur on separate hyphae or composite fruit bodies (conidiomata). These may or may not be differentiated into distinct conidiophores and/or conidiogenous cells (conidium-bearing hyphae or cells) which occur separately or are situated over the surface of or inside a conidioma. Some lack conidiomata and do not produce conidia but form other types of propagules. Conidium-, propagule-, or conidioma-bearing septate hyphae, or individual cells, constitute the vegetative thallus. The diagnostic feature of the group is the lack of a teleomorphic (sexual or perfect) state. There are more than 2500 accepted genera containing 21,000 species.