About this fungus
Eastern Jack-o'-lantern is a fungus in the Omphalotaceae family. Its habitat and field characteristics are summarised below.
A large, vivid pumpkin-orange mushroom that usually appears in substantial clusters around hardwood stumps, dead trunks or buried roots. Young caps are convex with an inrolled edge, then flatten and may become shallowly funnel-shaped while retaining a small central bump. Cap, gills, stem and cut flesh all carry orange tones.
What to check
Turn the cap over and look for narrow, sharp-edged true gills that are crowded, mostly unbranched and run down the stem. The solid stem tapers towards its base and has no ring or volva. A spore print is white, cream or pale yellow, not orange or rusty. Check the attachment to exposed or buried hardwood and the tightly clustered growth. Fresh gills can sometimes give a faint green light after the eyes adjust to complete darkness, but many collections do not glow visibly and a failed glow test means nothing.
Variation
Colour ranges from yellow-orange to deep pumpkin orange and may darken towards the stem base. The cap moves from convex to flat, depressed or shallowly vase-shaped as it expands, and old margins may turn upwards and become wavy. A central bump can persist even in a depressed mature cap. Fruiting bodies that emerge from buried roots can look as though they are growing directly from soil or lawn grass.
Lookalikes
Chanterelles share the orange colour but have blunt, wrinkled ridges that are part of the cap flesh, not thin blade-like true gills. Chanterelles arise from soil in a mycorrhizal relationship and are usually single or scattered rather than tightly clustered from wood. False Chanterelle has repeatedly forked gills and is generally smaller. Geography also matters: Omphalotus olearius is the similar southern European species, Omphalotus olivascens occurs in western North America and Omphalotus subilludens is associated with the Gulf Coast and subtropical eastern North America. Colour or bioluminescence alone cannot settle the identification.
Habitat and range
Saprobic on dead hardwood, especially oak, decomposing stumps, trunks and buried roots. Clusters often appear at the base of a living or dead tree and can emerge several metres away where a root remains underground. Fruiting is mainly from late summer into autumn. Omphalotus illudens is widespread in North America east of the Rocky Mountains and occurs more locally in northern and north-temperate Europe, while related jack-o'-lantern species occupy other regions.
Food safety
Poisonous.
Photographs
Adam Arendell / CC BY-SA 3.0
walt sturgeon / CC BY-SA 3.0