Mycena luxaeterna, commonly known as the eternal light mushroom, is a species of fungus in the family Mycenaceae.

Their thin, cylindrical, hollow, fragile stems up to 8 mm (0.31 in) in diameter are covered in a thick gel and emit a constant yellow-green bioluminescence (the caps do not glow).

[1] The mushroom was discovered in a very limited area of the Atlantic rain forest of São Paulo, Brazil and is known to exist only at this location.

It grows on decomposing twigs, rarely on dead leaves or undergrowth, in clusters of two-to-twenty individuals.

[1] The eternal light mushroom has no known nutritional value, contains no known hallucinogens, and is not reported as having any particular cultural significance.