Pustula helianthicola Rost & Thines, 2011
Helianthus annuus © Howard F. Schwartz, Colorado State University, Bugwood.org
same leaf, underside
hypophyllous dull white spots, pustules, even crusts, largely consisting of a mass of conidia. Embedded in the plant tissue, often near vascular bundles, lie ± light brown oospores, of which the walls exhibit an irregular reticulate structure.
Until recently it was assumed that Pustula obtusata was parasitising on a large number of Asteraceae genera, sunflower included. Rost & Thines found that at least the Pustula on Helianthus is a separate species, and they do not exclude the possibility that more species will have to be split off from obtusata.
A pest species in the sunflower-oil industry.
Beenken & Senn-Irlet (2016a), Jage, Klenke, Kruse ao (2017a), Klenke & Scholler (2015a), Kruse (2019a), Kruse, Thiel, Brodtbeck ao (2017a), Lava, Heller & Spring (2013a), Rost & Thines (2011a), Thines, Zipper & Spring (2006a).