silphium

Silphium is a genus of North American plants in the sunflower tribe within the daisy family.Members of the genus, commonly known as rosinweeds, are herbaceous perennial plants growing to 0.2 m (8 in) to more than 2.5 m (8 ft 2 in) tall, with yellow (rarely white) flowerheads that resemble sunflowers. In the rosinweeds, the outer florets in the head are fertile and the inner florets are sterile; in the sunflowers, the reverse is true.The name of the genus comes from the Ancient Greek word for a North ...