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, The
spores of
C. stercoreus are roughly spherical and relatively large, with typical dimensions of 20–35 x 20–25
μm, The spores are
sessile (growing directly from the surface of the basidium, without attachment via a
sterigmata), and are separated from the basidia after it collapses and gelatinizes. This is accompanied by the gelatinization of the inner walls of the peridiole. Further, the funicular cord, known to be highly elastic and with a high
tensile strength, is made of thicker hyphae than the rest of the funiculus. Brodie reported discovering a slender-stemmed "twinned" form, with two fruiting bodies originating from the same stalk. As has been shown in laboratory-grown specimens, the development and form of the fruiting bodies is at least partially dependent on the intensity of light it receives during development. For example, exposure of the
heterokaryotic mycelium to light is required for fruiting to occur, and furthermore, this light needs to be at a
wavelength of less than 530
nm. Lu suggests that certain growing conditions – such as a shortage in available nutrients – shifts the fungus'
metabolism to produce a hypothetical "photoreceptive precursor" that enables the growth of the fruiting bodies to be stimulated and affected by light. The fungi is also positively
phototrophic, that is, it will orient its fruiting bodies in the direction of the light source.
Life cycle The life cycle of
C. stercoreus, which contains both
haploid and
diploid stages, is typical of taxa in the
basidiomycetes that can reproduce both asexually (via
vegetative spores), or sexually (with
meiosis).
Basidiospores produced in the peridioles each contain a single haploid nucleus. After dispersal, the spores germinate and grow into
homokaryotic hyphae, with a single nucleus in each compartment. When two homokaryotic hyphae of different
mating compatibility groups fuse with one another, they form a
dikaryotic (containing two nuclei) mycelia in a process called
plasmogamy. After a period of time (approximately 40 days when grown from
pure culture in the laboratory) and under the appropriate environmental conditions, fruiting bodies may be formed from the dikaryotic mycelia. These fruiting bodies produce peridioles containing the
basidia upon which new basidiospores are made. Young basidia contain a pair of haploid sexually compatible nuclei which fuse, and the resulting diploid fusion nucleus undergoes meiosis to produce haploid basidiospores. == Habitat and distribution ==