The liberty cap is a small but globally famous mushroom that has naturalised in New Zealand environments. Named for its resemblance to the Phrygian cap used as a symbol of liberty in the classical world, the species features a distinctive, conical cap with a prominent, nipple-like point at the apex. The colour varies from a deep chestnut brown when wet to a lighter, straw-yellow when dry, often displaying a gelatinous, peeling surface layer. Beneath the cap, the gills are initially pale, maturing to a dark purple-brown as the spores develop. The stem is thin, fibrous, and flexible, typically matching the paler colour of the dried cap. Because of its subtle appearance, it is frequently confused with other, non-psychoactive mushroom species, which poses a significant risk to those who attempt to identify it in the wild. Ecologically, the liberty cap acts as a specialist saprotroph, feeding on decaying grass roots and organic soil matter. It is typically found in meadows, pastures, and grassy slopes where the soil is moist and nutrient-rich. Unlike many forest-dwelling fungi, it does not rely on wood for its growth, which allows it to thrive in open, human-modified habitats like suburban lawns, parks, and agricultural land. Its mycelium spreads slowly through the top layers of the soil, producing fruit bodies in the cool, damp conditions of autumn. As an introduced species, it has successfully established a widespread distribution throughout the country, effectively colonising the niches vacated by native grassland fungi or creating new ones in disturbed environments. In New Zealand, the liberty cap is perhaps best known for its psychoactive properties. It contains psilocybin and psilocin, substances that are classified as controlled drugs under the Misuse of Drugs Act. Consequently, the harvest, possession, and consumption of this mushroom are illegal. This legal status means that the species is rarely studied in a conventional conservation or botanical context, and it is largely treated as a prohibited item rather than a subject of natural interest. However, for mycologists, it remains an intriguing example of a non-native fungus that has managed to integrate into the New Zealand landscape with remarkable success. The fungus serves as a reminder of how species can travel globally via human activity, colonising new ecosystems far from their original range. Observers are advised to view it as a part of the ecological fabric of modified grasslands, while remaining aware of the strict legal and safety protocols surrounding it.