Helianthus cf. x laetiflorus, Belgium, prov. Antwerp, Meerhout © Carina Van Steenwinkel

infected leaf, upperside

underside

conidiophores

detail

conidia

gall

upper side of the leaf with pale spots. Underside there with a white down of erect conidiophores that apically several times are branching, each branch ending in a conidium.

host plants

Asteraceae, oligophagous

Bidens cernuus, comosus, connatus, frondosus, laevis, pilosus, vulgatus; Helianthus annuus, laetiflorus.

synonyms

Plamsopara helianthi Novotelnova, 1962. Moreover, Negrean & Anastasiu (2006a) cite P. angustiterminalis and carthami as synonyms of halstedii.

notes

originally a North American species.

hyperparasites

Cladosporium uredinicola.

references

Anon. (2008a), Brandenburger (1985a), Choi, Kiss, Vajna & Shin (2009a), Duarte, Choi, Soares & Barreto (2014a), García-Blázquez, Constantinescu, Tellería & Martín (2007a), Guatimosim, Pinto, Pereira, Fuga, Vieira & Barreto (2015a), Jage, Klenke, Kruse ao (2017a), Jage, Kruse, Kummer ao (2013a), Klenke & Scholler (2015a), Kruse (2019a), Müller (2015a), Mułenko, Piątek, Wołczańska ao (2010a); Negrean & Anastasiu (2006a), Riethmüller, Voglmayr, Göker, Weiß & Oberwinkler (2002a).