Witches' Butter

October 31, 2010

Photographer: James Van Gundy 
Summary Authors: James Van Gundy; Jim Foster

Still undecided about which treats to hand out this year? Perhaps witches' butter will be a hit with the trick-or-treaters. Witches' Butter (Tremella mesenterica) is one of the so-called jelly fungi. It's a parasite of the Crust fungi (Peniophora spp.) that are important decomposers of dead wood. Fungi play a critical role in breaking down dead plant materials in the Earth's terrestrial ecosystems. While many fungi are decomposers and quite a few are parasitic, a much larger number are involved in symbiotic associations with green plants. Nearly all species of higher plants have one or more species of a type of fungus called "mycorrhizae" associated with their roots. The plant supplies the fungus with food while the fungus greatly enhances the plant's ability to absorb water and nutrients from the soil. Many species of mushrooms are actually the fruiting structures of these mycorrhizal fungi. The gray-green patches in this photograph are lichens, which also have a symbiotic association between fungi and green plants. Although lichens appear to be a single organism, they're actually a species pair containing a fungus and either a green, or a blue-green, (cyanobacterium) alga. The alga cells supply the pair with food while the fungal tissue makes up the structural body of the lichen. So get ready to dish out the "butter" -- and be prepared for a trick or two and maybe a lawsuit as well.

Photograph taken in the Monongahela National Forest of West Virginia on June 20, 2009.

Photo details: Camera Maker: SONY; Camera Model: DSLR-A100; Focal Length: 70.0mm (35mm equivalent: 105mm); Aperture: f/5.6; Exposure Time: 0.0080 s (1/125); ISO equiv: 400; Exposure Bias: none; Metering Mode: Matrix; Exposure: program (Auto); White Balance: Auto; Light Source: Unknown; Flash Fired: Yes (Auto); Color Space: sRGB.