any member of a large group of fungi (kingdom Fungi) in the order Pezizales (phylum Ascomycota) and typically characterized by a disk- or cup-shaped structure (apothecium) bearing spore sacs (asci) on its surface. Some of the cup fungi are important plant pathogens, such as Monilinia (Sclerotinia), causing brown rot in peach and other stone fruits. Others are saprobes, displaying small (2-5 mm [0.08-0.2 inch]), brilliant red or orange disks found on old cow dung and decaying twigs and branches. Each ascus usually contains eight ascospores. Apothecia are usually open to the exterior; however, in subterranean truffles, the apothecia are completely enclosed, exposed only when the truffle is opened. Many of the cup fungi produce ballistospores, ascospores that are forcibly shot out. Sometimes, as in Helvella and Peziza, they are discharged in such numbers that they form a cloud above the fruiting body, and innumerable tiny explosions may be heard as a hissing sound
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