Omphalotus olearius, commonly known as the jack-o'-lantern mushroom, is a poisonous orange gilled mushroom that to an untrained eye appears similar to some chanterelles. It is notable for its bioluminescent properties. It is found in woodland areas in Europe, where it grows on decaying stumps, buried roots or at the base of hardwood trees. A similar, but phylogenetically distinct species found in eastern North America is Omphalotus illudens.