Also found in: Medical, Encyclopedia.


 (yo͝or′ĭ-dĭn′ē-əm) also u·re·di·um (yo͝o-rē′dē-əm)
n. pl. u·re·din·i·a (-dĭn′ē-ə) also u·re·di·a (-dē-ə)
A reddish pustulelike structure that is formed in the tissue of a plant infected by a rust fungus and produces urediniospores.

[New Latin ūrēdinium, from Latin ūrēdō, ūrēdin-, blight, from ūrere, to burn.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(jʊˈriːdɪəm) or


n, pl -dia (-dɪə) or -dinia (-ˈdɪnɪə)
(Botany) a spore-producing body of some rust fungi in which uredospores are formed. Also called: uredosorus
[C20: from New Latin, from uredo]
uˈredial adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
Mentioned in ?
References in periodicals archive ?
Symptoms appear after one week of infection as yellow to orange colored rust pustules known as uredium. These rust pustules get their name from the characteristic that resemble with the fresh rust on iron.
0 represented highly resistant with no symptom, 0; represented small necrosis but no sporulation, 0;+ represented larger or necrosis without sporulation, 1 represented some necrosis with only a trace of to slight sporulation, 1+ for chlorosis and necrosis associated with 1imited uredium development, 2 represented chlorosis flecks or necrosis with moderately sporulation, 2+ for chlorosis and necrosis among abundant - to get the F1 seeds and the F1 plants were self-pollinated to interrnediate spolulation, 3 for chlorosis and necrosis obtain F2 seeds, which were used in allelic analysis reseach; MX169 as female and male was crossed with Early Premium.
When the flag leaf, whose distance is about among increased uredium development, 3 represented extensive sporulation production with some chlorosis, 3+ represented chlorosis flecks or necrosis with moderately sporulation, and 4 represented susceptible.