Bot. a pustule, often found on the epidermis of grasses, formed by a rust fungus and consisting of uredospores
Origin of urediniumModern Latin ; from Classical Latin uredo (gen. uredinis), blight: see uredo and amp; -ium
nounpl. u·re·din·i·a also u·re·di·a
A reddish pustulelike structure that is formed in the tissue of a plant infected by a rust fungus and produces urediniospores.
Origin of urediniumNew Latin ūrēdinium, from Latin ūrēdō, ūrēdin-, blight, from ūrere, to burn.