Omphalotus olivascens

Omphalotus olivascens
Scientific classification
Kingdom:	Fungi
Division:	Basidiomycota
Class:	Agaricomycetes
Order:	Agaricales
Family:	Marasmiaceae
Genus:	Omphalotus
Species:	O. olivascens
Binomial name
Omphalotus olivascens H.E.Bigelow, O.K.Mill. & Thiers (1976)

Omphalotus olivascens
Mycological characteristics
	gills on hymenium
	cap is infundibuliform
	hymenium is decurrent
	stipe is bare
	spore print is yellow
	ecology is saprotrophic
	edibility: poisonous

Omphalotus olivascens, commonly known as the western jack-o'-lantern mushroom, is an orange to brown-colored gilled mushroom native to California and Mexico.

The fungus was described as new to science in 1976 by American mycologists Howard E. Bigelow, Orson K. Miller, Jr., and Harry D. Thiers. A subspecies with blue flesh, O. olivascens var. indigo, was described growing on live oak in Baja California, Mexico.

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. Molecular analysis shows the jack-o'-Lantern to be most closely related the ghost fungus Omphalotus nidiformis. Miller notes that the colours and shades of the ghost fungus most closely resemble this species.

To an untrained eye, O. olivascens appears similar to some chanterelles, but unlike the chanterelle, the jack-o'-lantern mushroom has true gills (rather than ridges) and it can have olive coloration that chanterelles lack; also, Omphalotus species are saprotrophic, grow directly on wood, and are bioluminescent.

A saprobe or parasite, O. nidiformis is nonspecific in its needs and is compatible with a wide variety of hosts.

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Wikipedia