dung-loving bird's nest fungus

The fruiting bodies, or perida, are funnel- or barrel-shaped, 6–15 mm tall, 4–8 mm wide at the mouth, sometimes short-stalked, golden brown to blackish brown in age. The outside wall of the peridium, the ectoperidium, is covered with tufts of fungal hyphae that resembles shaggy, untidy hair. However, in older specimens this outer layer of hair (technically a tomentum) may be completely worn off. The internal wall of the cup, the endoperidium, is smooth and grey to bluish-black. The 'eggs' of the bird's nest – the peridioles – are blackish, 1–2 mm in diameter, and there are typically about 20 in the cup. Peridioles are often attached to the fruiting body by a funiculus, a structure of hyphae that is differentiated into three regions: the basal piece, which attaches it to the inner wall of the peridium, the middle piece, and an upper sheath, called the purse, connected to the lower surface of the peridiole. In the purse and middle piece is a coiled thread of interwoven hyphae called the funicular cord, attached at one end to the peridiole and at the other end to an entangled mass of hyphae called the hapteron. However, Brodie reports that sometimes C. stercoreus is found without a funiculus, which has led some authors to misidentify this species with the genus Nidula.

The spores of C. …

Being coprophilous, C. stercoreus grows on dung, in soil with dung, and bonfire sites; it has also been recorded growing on sand dunes. The fungus is known to have a worldwide distribution, and Curtis Gates Lloyd, in his monograph on the Nidulariaceae, wrote that it "probably occurs in every country where manure occurs".

In Traditional Chinese medicine, a decoction of this fungus is used to help relieve the symptoms of gastralgia, or stomach ache.

Cyathus stercoreus has been investigated for its ability to break down lignin and cellulose in agricultural byproducts, like wheat straw or grasses. It selectively breaks down lignin, leaving much of the cellulose intact, which increases the amount of digestible carbohydrate for ruminant mammals, and enhances both its value as a food source and its biodegradability. The enzymes responsible, laccase and manganese peroxidase, also have industrial applications for lignin degradation and removal in the pulp and paper industry. Liquid cultures of C. stercoreus have also been shown to biodegrade the explosive compound 2,4,6-trinitrotoluene (TNT).