Jeffersonia, also known as twinleaf or rheumatism root, is a small genus of herbaceous perennial plants in the family Berberidaceae.

Jeffersonia was named for United States President Thomas Jefferson by his contemporary Benjamin Smith Barton.

Twinleaf is protected by state laws as a threatened or endangered plant in Georgia, Iowa, New York, and New Jersey.

[3] In Minnesota it grows in the lower southeastern section of the state in mesic deciduous forests and most commonly in ravines or on talus slopes.

The Cherokee use an infusion of this plant for treating dropsy, as well as gravel and urinary tract problems, and as a poultice for sores and inflammation.