uredinium

noun

ure·​din·​i·​um ˌyu̇r-ə-ˈdi-nē-əm 

plural uredinia ˌyu̇r-ə-ˈdi-nē-ə 

: a usually reddish or black mass of hyphae and spores of a rust fungus forming pustules that rupture the host's cuticle

uredinial

ˌyu̇r-ə-ˈdi-nē-əl 

adjective

Word History

Etymology

New Latin, from Latin uredin-, uredo burning, blight, from urere to burn — more at ember

First Known Use

1905, in the meaning defined above