Found just once in southern Brazil, the glowing Mycena abieticola
mushroom (seen above in daylight, top, and at night) had previously been identified in Mexico
, where it grows on fir trees, an October 2009 study says.
All glowing fungi emit a yellowish green color in the same wavelength of light, San Francisco State University's Desjardin said.
The brilliance occurs through a poorly understood chemical process that's similar to the mechanism by which fireflies produce light, he added.
Photograph courtesy Cassius V. Stevani, University of Sao Paulo, Brazil