Like a black light poster come to life, a group of bioluminescent fungi collected from Ribeira Valley Tourist State Park near Sao Paulo, Brazil, emanates a soft green glow when the lights go out.

The mushrooms are part of the genus Mycena, a group that includes about 500 species worldwide. Of these only 33 are known to be bioluminescent--capable of producing light through a chemical reaction.

Since 2002 Cassius Stevani, professor of chemistry at the University of Sao Paulo; Dennis Desjardin, professor of mycology at San Francisco State University in California; and Marina Capelari of Brazil's Institute of Botany have discovered ten more bioluminescent fungi species--four of which are new to science--in Brazil's tropical forests.

The work, Stevani says, has increased the number of glowers known since the 1970s by 30 percent.