Helianthus annuus L., alias Sunflower, Sunflower, Sunflower, etc., belongs to panicum miliaceum of Compositae. It is used as medicine with inflorescence receptacle (disk) and seeds, which has the effects of nourishing liver and kidney, lowering blood pressure and relieving pain, and is planted all over the country.

Liedang, also known as root grass, poisonous root grass and rabbit crutch, is an important parasitic weed in sunflower planting areas, which is mainly distributed in Hebei, Beijing, Xinjiang, Shanxi, Inner Mongolia, Heilongjiang, Liaoning, Jilin and other provinces in China. There are a wide range of host plants, except sunflower, which can also harm watermelon, melon, pea, broad bean, carrot, celery, tobacco, flax, tomato and other plants.