About this fungus
Blistered Cup is a fungus in the Pezizaceae family. Its habitat and field characteristics are summarised below.
A stout pale cup fungus that often appears in crowded, distorted clusters on manure-rich straw or compost. Young fruit bodies can look like hollow bladders with a small opening and a thick inrolled rim. As they expand, the opening tears wider and the pale ochre to yellow-brown inner surface becomes visible, sometimes with rounded swellings that give the species its common name.
What to check
Start with the substrate and growth pattern. Typical fruit bodies are tightly clustered on manure, rotting straw, compost or heavily fertilised soil, where neighbouring cups press one another into angular shapes. The inner fertile surface is smooth to blistered and yellow-brown, buff or ochre-cream. The outer surface is paler, scurfy or finely granular. The flesh is brittle, there is no true stem, and gills, ring and volva are absent. Other Peziza species overlap strongly, so smooth spore dimensions and tissue characters are needed for a defensible species record.
Habitat and range
Saprotrophic on nitrogen-rich organic matter, especially manure heaps, dung mixed with straw, stable bedding, compost and richly fertilised garden soil. It can form large crowded flushes and may appear through much of the year where heaps remain damp and warm, rather than following one simple woodland season. The species is reported across Europe, North America and other temperate and subtropical regions, often in farm, garden and park settings.
Food safety
Poisonous.