Omphalotus illudens
Images by Michael Wood
Hygrophoropsis aurantiaca, also known as the false chanterelle, is a mushroom species that is found in North America and Europe.
Description
Omphalotus illudens, commonly called the eastern jack-o'lantern mushroom, is a sizable orange fungus often found in clusters on decaying stumps or at the base of hardwood trees in eastern North America. When fresh, its gills may emit a faint green glow, lasting up to 40–50 hours after picking. This luminosity is thought to attract insects at night, aiding in spore distribution.
Though sometimes confused with edible chanterelles, the Eastern jack-o'lantern can be identified by its thicker, fleshy appearance, tendency to cluster, and distinct caps when young. Unlike chanterelles, it is toxic to humans, causing vomiting, cramps, and diarrhea when consumed, whether raw or cooked. Despite historical confusion with Omphalotus olearius, genetic analysis confirms them as separate species.
1. Cap: The cap of the jack-o'-lantern mushroom is convex to flat when mature, ranging in diameter from 5-20 cm (2-8 inches). It has a smooth and slightly sticky surface that is often bright orange to orange-yellow in color. The cap margin is typically wavy or irregular.
2. Gill: The gills of the jack-o'-lantern mushroom are close and decurrent, meaning they run down the stem. They are thick, forked, and emit a bioluminescent glow in the dark, especially when the mushroom is fresh. The gill color is initially yellow but turns rusty or orange-brown as the spores mature.
3. Stem: The stem of the jack-o'-lantern mushroom is typically cylindrical, ranging from 5-10 cm (2-4 inches) in height and 1-2 cm (0.4-0.8 inches) in thickness. It has a firm and fibrous texture, often tapering towards the base. The stem color is similar to the cap, with a bright orange to orange-yellow hue.
4. Spore Print: The spore print of the Eastern jack-o'-lantern mushroom is yellow.
5. Habitat: The jack-o'-lantern mushroom is typically found growing in clusters or overlapping groups on decaying wood, such as tree stumps, logs, or buried roots. It is most commonly associated with hardwood trees, including oaks and maples. The mushroom can be found in forests, woodlands, and sometimes even urban areas.
Illudin S and illudin M, toxic compounds found in Omphalotus illudens, are responsible for the mushroom's toxicity when consumed. These chemicals, while having antibacterial and antifungal properties, are harmful to humans if the mushrooms are eaten raw or cooked. Although muscarine is suggested to contribute to toxicity, further studies are needed to confirm its presence in O. illudens.
Illudin S, despite its toxicity, has intrigued researchers for its cytotoxic effects on certain cancers. To make it usable, it undergoes chemical modifications. Within human cells, illudin S interacts with DNA, causing a specific type of damage that inhibits transcription. This damage can only be repaired by a system called nucleotide excision repair. MGI Pharma has developed an illudin-derived compound, Irofulven, for potential cancer treatment, but its application is still in the experimental phase.
