The common name for the mushroom species Clitocybe illudens is the "Jack O'Lantern mushroom." It is named as such because of its glowing property, where the gills emit a faint greenish glow in the dark. This mushroom is often associated with Halloween due to its eerie appearance and luminescence. However, it's important to note that the Jack O'Lantern mushroom should not be confused with the pumpkin-carved lanterns commonly seen during Halloween, as the mushroom is not safe for consumption and can be toxic if ingested.