a binucleate spore borne in a uredinium and capable of infecting the same host on which it originated, usually echinulate.

A binucleate repeating spore borne in the uredinium. (Uredinales) (Also uredospore, urediospore.) ( 15)

Urediniospores are the thinner-walled spores of some fungi: (rusts and smuts), from which the basidium arises.