aecidium 🔊 Listen to this < /iˈsɪd i ə/. Mycology. an aecium in which the spores are always formed in chains and enclosed in a cup-shaped peridium. Aecidium – Wikipedia Aecidium berberidis spores Stock Photo: 155567359 – Alamy Aecidium – Wikipedia Aecidium rhamni Share Facebook Twitter Google +