Panaeolus antillarum is a species of mushroom in the family Bolbitiaceae.

 

• Cap: 3 to 6 cm, bell-shaped to convex, white to light gray or yellowish. The caps are thick, smooth, often with fine wrinkles and acquire a silver white shiny color in age.
• Gills: Gray in young specimens, turning black as the spores mature.
• Spore print: Black.
• Stipe: 4 to 22 cm long and .5 to 2 cm thick, solid, sometimes slightly larger at the base.
• Taste: Fungal.
• Odor: Fungal.
• Size: Small to medium.
• Microscopic features: Spores ellipsoid, 15 - 20 (21) x 10 - 14 x 8 - 10(11) μm. Cheilocystidia cylindrical to narrowly utriform, colorless, 30 - 45 μm. Sulphidia clavate, sometimes with a stalk, 25 - 50 μm. Basidia four spored, 30 - 35 micrometers long.

Similar species: It is often mistaken for Panaeolus semiovatus var. phalaenarum or Panaeolus cyanescens, the latter species can be distinguished by the thinner, grayer cap and blue bruising.

Distribution and habitat: It´s common and widely distributed. It grows on dung. It is found from northern North America through Mexico into northern South America.

Uses: It is edible but not commonly eaten.