Uromyces silphii Arthur, 1907
Aecia yellow, cupulate, on discoloured spots at the underside of the leaves.
Uredinia and telia amphigenous, light and dark brown, respectively. Urediniospores with two pores above the equator. Teliospores one-celled, smooth, wall apically strongly thickened; pedicel at least as long as the spore (up to 35 µm), often deciduous.
Juncaceae, narrowly monophagous
This North American species was first discovered in Central Euope in 1956. The occurrence on Silphium seems not yet to be confirmed in Europe.
Beenken & Senn-Irlet (2016a), Brandenburger (1985a), Gäumann (1959a) Jage, Kruse, Kummer ao (2013a), Klenke & Scholler (2015a), Kruse (2014a), Melzer, Pittoni, Poelt & Scheuer (1984a), Mułenko, Piątek, Wołczańska ao (2010a), Poelt & Zwetko (1997a), Termorshuizen & Swertz (2011a), Woods, Stringer, Evans & Chater (2015a).