Hydnellum peckii. Photo Credit: Bernypisa [CC BY-SA 3.0], via Wikimedia Commons.
In the same way that you may have to be convinced that a raisin really used to be a grape before it aged and dried out, you also might be surprised to learn about the difference between a young Bleeding Tooth Fungus (Hydnellum peckii) and its adult counterpart. The adult mushroom is beige and rather dull in appearance. When young and actively growing, however, this whitish mushroom appears to bleed from its pores, inspiring some of its colorful names (it's also known as Devil's Tooth).
This gooey red liquid is actually a sap of sorts caused by a process called guttation. When the soil surrounding the fungus' root system becomes very wet, it may force water into the roots through the process of osmosis. This creates pressure throughout the organism, which eventually builds up enough to force liquid to the surface of the fungus. Although scientists have not yet decided what this liquid is exactly, they know it appears red thanks to a pigment found within the fungus.
In addition to its most graphic feature, the Bleeding Tooth Fungus has small toothlike projections underneath the mushroom cap, where its spores are produced. When young, the mushroom's surface is covered in soft "hairs" that can give it a velvety texture, but these fall off as the mushroom matures. As with similar fungi, beneath each mushroom lies an interconnected mass of mycelia, its root system. The mycelia can spread widely just beneath the surface of the forest floor—up to 11 feet away from where the mushroom appears.
Located in forested, often mountainous, areas in North America, Europe, Iran, and South Korea, the Bleeding Tooth Fungus has a symbiotic relationship with the coniferous trees amongst whose roots it is located. The trees provide the fungus with access to a fixed source of carbon dioxide, while the fungus produces enzymes that convert amino acids and minerals found in the soil into forms that the host trees can better use. The fungi's presence is indicative of an old, species-rich forest, and scientists express concern when it disappears from an area, as seems to be happening in areas of Europe, where nitrogen deposits caused by pollution may be a problem.
The Bleeding Tooth Fungus is not toxic, but tastes so bitter as to be inedible, despite one of its other names (Strawberries and Cream, because of its resemblance to a fruit danish). However, the mushroom is valued by natural dyers, who dry it and use it alone to create a beige dye or combine it with mordants (substances, such as allum or iron, that cause a dye to set into fabric and other surfaces) to create blue-green hues. Scientists have found that extracts from the Bleeding Tooth Fungus contain the chemical compound atromentin, which like heparin, can be used as an anti-coagulant to keep blood clots from forming and which also has anti-bacterial properties and may be an option for treating the most common strain of bacterial pneumonia. Researchers are also looking at another chemical found in the Bleeding Tooth Fungus, thelephoric acid, which may someday be used to treat Alzheimer's disease.
Learn more about other types of fungi in these Science NetLinks resources: Mycologist Debbie Viess leads an inventory of the mushrooms in Muir Woods as part of BioBlitz 2014 in Golden Gate National Parks. In this video, AAAS's Bob Hirshon talks with a team from the University of Arizona who are hunting for fungi that spend their entire lives inside plants. Listen to this Science Update to hear about a fungus attack in Italy that dates back to World War II. And in The Case of the Vanishing Golden Frogs lesson, find out what might be causing these amphibians to die off.
Are you interested in finding out more about symbiotic relationships? Listen to this Science Update on Three-Way Symbiosis. The Ecology of Your Skin lesson series deals with bacteria and microbes that live on our skin.