Omphalotus nidiformis, or ghost fungus, is a bioluminescent gilled mushroom that occurs primarily in southern Australia and Tasmania, and has been reported from India. The cream-coloured fan- or funnel-shaped caps, up to 30 cm (12 in) across, have shades of orange, brown, purple, or bluish-black. The white or cream gills run down the length of the stalk, which is up to 8 cm (3 in) long and tapers in thickness to the base. The fungus is both saprotrophic and parasitic, and its fruit bodies are generally found growing in overlapping clusters on a wide variety of dead or dying trees. First described scientifically in 1844, O. nidiformis (from Latin for 'nest-shaped') was known by several names before Orson K. Miller Jr. assigned its current name in 1994. Similar in appearance to the common edible oyster mushrooms, O. nidiformis is poisonous, with compounds called illudins that can produce severe cramps and vomiting. (Full article...)