Silphium radula, commonly known as roughstem rosinweed,[1] is a species of flowering plant in the family Asteraceae.

It is native North America, where it is found in the South Central region of the United States.

[3] The taxonomy of the genus Silphium remains unresolved in North America, with the appropriate ranks and relationships between the taxa unclear.

[3][4] Silphium radula can be distinguished from S. gracile by its shorter peduncles, resulting in its stem leaves often subtending the flower heads (as opposed to flowers being on long naked peduncles as in S. gracile).

[3][4] As for Silphium integrifolium, S. radula can be distinguished from it by having longer stem pubescence, and by the tendency of S. radula to have both alternate and opposite leaves (as opposed to the strictly opposite leaves of S.