The common bird’s nest fungus Crucibulum lavae (Basidiomycota, Agaricomycetes, Agaricales, Agaricaceae) is a common sighting on the MSU campus. It often grows on the woodchips that line flower beds all over campus, and are commonly found throughout the world in temperate and tropical climates. I found these specimens living on woodchips in a flower bed just west of the Old Horticulture building (506 East Circle Drive) on campus.
This species was first described by Hudson under the name Peziza laevis (Hudson 1778), and later moved into the genus Crucibulum by Kambly (1936). Perhaps due to its charming, conspicuous fruiting body, the species has many synonyms including Nidularia levis, N. Laevis, N. crucibulum, Peziza crucibuliformis, P. levis, P. pyxix, P. scutellaris, Cyanthus cylindricus, C. crucibuliformis, C. crucibulum, C. pezizoides, C. atrofuscus, Cyathella laevis, Crucibulum crucibuliforme, and C. vulgare (Mycobank).
This species is most easily identified by the macroscopic characters if the fruiting body. Young fruiting bodies grow from the substrate,
starting as tiny spheres and eventually growing into rounded inverted cones with the bottom having a smaller diameter than the top (Arora, 1976). The top is closed by a yellow covering until the cups open when mature. The fruiting bodies are deeply cup shaped and light yellow and shaggy on the outside (Arora, 1976). Their inner surface is smooth, with no striations and contain several white, lentil-shaped (sometimes ellipsoid) “eggs” called peridioles (Arora, 1976; Kuo & Methven, 2014). These are attached to the bottom of the cup by a cord (funiculus) that becomes flexible and sticky when moistened by
rain (Kuo, 2016). The spores develop inside the peridioles. They are football-shaped (7-10 x 3-6 µm), hyaline, and smooth (Kuo & Methven, 2014; Kuo, 2014).
Crucibulum laeve grows on leaf litter, especially wood chips and small twigs and branches. Spores disperse in a unique manner, relying on rainfall. When raindrops fall into the cups, the hydrated funiculus stretches and breaks, launching the peridiole free. When it lands, the funiculus sticks to the substrate, thus delivering the spores inside to a new area (Kuo, 2014).
Besides being interesting to look at and generally charismatic, this species is an important member of forest ecosystems within its range. It is part of the community that decomposes dead plant matter on the forest floor (Wicklow et al., 1984). Crucibulum laeve has also been the focus of recent investigations into sexual reproduction in the family Nidulariaceae (Malloure & James, 2013).
Arora, D. 1976. Mushrooms Demystified: a comprehensive guide to the fleshy fungi. Ten Speed Press: Berkeley, CA.
Crucibulum laeve. Mycobank.org. Accessed November 19, 2016.
EOL: Crucibulum laeve, Common bird’s nest. http://www.eol.org/pages/189161/maps. Accessed November 19, 2016.
Hudson. 1778. Flora Angelica. 2(2):634.
Kambly. 1936. University of Iowa Studies in Natural History. 17(4):167.
Kuo, M. 2014, February. Crucibulum laeve. http://www.mushroomexpert.com/crucibulum_laeve.html. Accessed November 20, 2016.
Kuo, M., and A.S. Methven. 2014. Mushrooms of the Midwest. University of Illinois Press: Urbana, Chicago, Springfield.
Malloure, B.D., and T.Y. James, 2013. Inbreeding depression in urban environments of the bird’s nest fungus Cyathus steroreus (Nidulariaceae: Basidiomycota). Heredity 110:355-365.
Wicklow, D.T., R. Langie, S. Crabtree, and R.W. Detroy. 1984. Degradation of lignocellulose in wheat straw versus hardwood by Cyathus and related species (Nidulariaceae). Canadian Journal of Microbiology 30(5) 632-618.104.22.168