Silphium (genus)

Silphium is a genus of North American plants in the tribe Heliantheae within the family Asteraceae.

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 African plant whose identity has been lost, though it is known its gum or juice was prized by the ancients as a medicine and a condiment.