Aecidium is a genus of rust fungi in the Pucciniales order. The widespread genus is estimated to contain about 600 species.

1. The aecidium forms on the leaves during the infection.
   感染過程中，孢子囊在葉子上形成。
2. Scientists studied the aecidia to understand the rust fungus life cycle.
   科學(xué)家研究了孢子囊以了解銹菌的生命周期。