The sexual spores of Ascomycetes are produced eight at a time in a sac called an ascus. This ascus, when introduced into a moist atmosphere, will rupture in various manners to release the spores into the air. Once in the air, the spores serve as dispersal units as they are carried by the wind. In the microscopic veiw below the ascospore-forming surface of an ascomycete fruiting body is shown with many ascus; each forms eight ascospores. Though the spores in some of the asci are obscured, others can clearly be seen to contain eight spores.
The individual ascospores are extremely variable in size and shape. Ascospores do not have an attachment peg or scar, however some are distinguished as they are surrounded my a clear mucilanginous layer. Also, some ascospores have a germ slit or germ pore. Ascospores can be single-celled or multicelllular. The images below show just a small selection of ascospores and their variability.