Omphalotus Nidiformis - Taxonomy and Naming

Taxonomy and Naming

The ghost fungus was initially described in 1844 by English naturalist Miles Joseph Berkeley as Agaricus nidiformis. Berkeley felt it was related to Agaricus ostreatus (now Pleurotus ostreatus) but remarked it was a "far more magnificent species". Material was originally collected by Scottish naturalist James Drummond in 1841 on Banksia wood along the Swan River. He wrote "when this fungus was laid on a newspaper, it emitted by night a phosphorescent light, enabling us to read the words around it; and it continued to do so for several nights with gradually decreasing intensity as the plant dried up." More material collected from near the base of a "sickly but living" Grevillea drummondii was named as Agaricus lampas by Berkeley. He noted both were phosphorescent and closely related species. Tasmanian botanist Ronald Campbell Gunn collected material in October 1845 from that state, which Berkeley felt differed from previous collections in having more demarcated and less decurrent gills and a shorter stipe, and named it Agaricus phosphorus in 1848. Italian mycologist Pier Andrea Saccardo placed all three named taxa in the genus Pleurotus in 1887. These names have been synonymised with O. nidiformis, although the name Pleurotus lampas persisted in some texts, including the 1934–35 monograph of Australian fungi by John Burton Cleland. In reviewing the published literature, Victorian botanical liaison officer Jim Willis was aware of Rolf Singer's placing of Pleurotus olearius into the genus Omphalotus, but stopped short of transferring the ghost fungus across, even though he conceded it was wrongly placed in Pleurotus. Investigating the species in 1994, Orson K. Miller, Jr. gave the ghost fungus its current binomial name when he transferred it to the genus Omphalotus with other bioluminescent mushrooms.

The specific epithet nidiformis is derived from the Latin terms nīdus 'nest' and forma 'shape' or 'form', hence 'nest shaped'. Lampas is derived from the Greek lampas/λαμπας 'torch'. Common names include ghost fungus and Australian glow fungus. Drummond reported that the local aborigines were fearful when shown the luminescent fungus and called out chinga, a local word for spirit; Drummond himself likened it to a will-o'-the-wisp. Likewise on the Springbrook Plateau in southeastern Queensland, the local Kombumerri people believed the lights to be ancestors and gave the area a wide berth out of respect.

The effect produced by it upon the traveller, when on a dark night he comes suddenly upon it glowing in the woods, is startling; for to a person unacquainted with this phenomenon the pale, livid, and deadly light emanating from it conveys to him an impression of something supernatural, and often causes no little degree of terror in weak minds or in those willing to believe in supernatural agencies.

Several Omphalotus species with similar bioluminescent properties occur worldwide, all of which are presumed poisonous. The best known are the North American jack o'lantern mushroom (O. olearius) and the tsukiyotake (O. japonicus (Kawam.) Kirchm. & O.K. Mill. (formerly known as Lampteromyces japonicus (Kawam.) Sing.), found in Japan and eastern Asia. A 2004 molecular study shows the ghost fungus to be most closely related to the western jack o'lantern mushroom (O. olivascens), which is abundant in Southern and Central California. Miller notes that the colours and shades of the ghost fungus most closely resemble this species.

Laboratory breeding experiments with it and other Omphalotus species have revealed a low level of compatibility (ability to breed and produce fertile hybrids), suggesting it is genetically distinct and has been isolated for a long time. It is particularly poorly compatible with O. illudens, the authors of the study suggesting the separation may have been as long ago as the Late Carboniferous separation of Gondwana from Laurasia but conceding the lack of any fossil record makes it impossible to know whether the genus even existed at the time.