pycnidium

pycnidium, variable and complex flask-shaped asexual reproductive structure, or fruiting body, in fungi (kingdom Fungi) of the phylum Ascomycota; also a male sex-cell-producing organ in the order Uredinales (rust fungi). It bears spores (conidia) variously known as pycnidiospores, oidia, or spermatia. The spores are liberated through an opening (ostiole) in the pycnidium.