In the Uredinales the first sorus that is formed after plasmogamy and bears binucleate aeciospores (Stage I heteroecious or autoecious rusts). (Pl. aecia.) ( 15)
(pl. aecia) - One of the reproductive structures in the life cycle of a rust fungus. Aecia normally appear as blisters on the host plant.
(pl. aecia): A club-shaped fruiting body of the rust fungi which produces aeciospores.