The irregularly distributed asci contain eight unicellular ascospores each. These ascospores are globose and located in asci. The ascospores frequently bud into multiple yeast cells within the asci. The asci in the pseudothecia produce ascospores that can then infect plants. The perithecia hold a layer of asci which contain the ascospores. This ball contains the asci and ascospores. Ascospores are hyaline, uniformly filamentous, and spirally flexed within asci. Karyogamy in the asci is followed immediately by meiosis and the production of ascospores. An ascus (plural "asci") is then formed, in which karyogamy (nuclear fusion) occurs. Interspersed among the asci are threadlike sterile cells called paraphyses. The asci are present in the hymenium layer. Sordariomycetes generally produce their asci in perithecial fruiting bodies. None has ascogenous hyphae giving rise to the asci. Further growth makes the hymenium convex with the asci facing towards the outer side. Ascospores are borne within sac-like structures called asci, which are contained within the sporocarp.