Coptis

Coptis, a genus of Ranunculaceæ. C. trifoliata, called Gold Thread on account of the appearance and colour of its rhizomes, is a native of swamps in the colder northern regions of both hemispheres. It has ternate leaves and solitary white flowers. The bitter rhizomes are used in America as a tonic, and as a yellow dye. That of C. teeta of Assam is used in India as a bitter tonic.