Yellow toadflax can out-compete native plants, which negatively affects plant crops, and reduces grass growing in pastures and rangelands.

Why is toadflax an invasive species?

On rangelands, an invasion of yellow toadflax alters the species composition of natural communities and reducing forage production for livestock and wildlife. This in turn reduces rangeland value and can lead to erosion problems.

Why is yellow toadflax bad?

Although cattle avoid grazing the species, yellow toadflax contains a poisonous glucoside harmful to cattle if consumed in large quantities. ... It was first introduced into the United States from Wales during colonial time as an ornamental species and to make yellow dye, and escaped from colonial gardens (Mitich 1993).