Helianthus divaricatus, or the woodland sunflower, is a wild sunflower species native to North America that is part of the tertiary genepool of the cultivated sunflower crop. This means that many reproductive barriers exist between H. divaricatus and cultivated sunflower, and even when hybridization is successful, the resulting progeny are usually sterile.
Helianthus divaricatus has been identified as a source of resistance to broomrape (Orobanche cumana Wallr.) and downy mildew (Plasmopara halstedii (Farl.= Berl. and de Toni). [1]
