The Washington State Department of Agriculture (WSDA) confirmed the first detection of sunflower broomrape (Orobanche cumana) in North America. It is a destructive parasitic weed. The discovery was made in Yakima, Washington.

The plant was first identified by a homeowner and confirmed through WSDA’s diagnostic lab and the USDA Animal and Plant Health Inspection Service (APHIS). Native to Eurasia, sunflower broomrape is a root parasite that attacks sunflowers and other members of the Asteraceae family.

Because the parasite cannot photosynthesize, it relies entirely on its host plant for survival. This leads to severe crop losses. Its aggressive spread and ability to produce hundreds of thousands of long-lasting seeds make it extremely difficult to eradicate once established.

This discovery is considered a serious threat to sunflower growers, processors, exporters, and the agricultural economy across North America. WSDA is working with USDA and local stakeholders to investigate the source and determine the extent of the infestation. WSDA will then develop response and containment strategies.

The public is being asked to assist by reporting suspected sightings. Suspected plants should not be disturbed to avoid spreading seeds. Individuals are urged to take photos and report findings to WSDA via email (pest@agr.wa.gov).

Read more about the first reported sighting of sunflower broomrape in North America here.