Xanthorhiza simplicissima (yellowroot) is the only member of the genus Xanthorhiza, and one of very few genera in the family Ranunculaceae with a woody stem (the other notable example being Clematis). It is native to the eastern United States from Maine south to northern Florida and west to Ohio and eastern Texas. It contains the alkaloidberberine, which has a number of traditional and contemporary uses for dyeing and medicine.
The genus name as well as the common name refer to the plant's yellow roots (xantho- meaning "yellow" and rhiza meaning "root"), which was used to produce a yellow dye by Native Americans. The specific epithet refers to the simple (not branched) stems.[1]
Description
In the wild, it grows on the edges of streams in sandy soil under a canopy of dappled sunlight. In cultivation, it is often provided with more sunlight so that the fall colors are more vivid. It is a subshrub, reaching 20–70 centimetres (8–28 in) (rarely 90 centimetres (35 in)) in height, with stems up to 6 millimetres (0.24 in) diameter. The leaves are spirally arranged, 10–18 centimetres (4–7 in) long, each divided into 5 toothed leaflets, and flowers emerge only from the upper portion of the unbranched stem. The flowers are produced in broad panicles 6–20 centimetres (2–8 in) long, each flower small, star-shaped, reddish brown to purple brown, with five petals.
Yellowroot propagates asexually by sending out many underground runners, and it reproduces sexually with seeds.
American Indians used the root tea for stomach ulcers, colds, jaundice, sore mouth or throat and as an astringent. A folk remedy used in the South for diabetes and hypertension. This species contains berberine, which is an anti-inflammatory, astringent, hemostatic, antimicrobial, anticonvulsant and immunostimulant. Berberine also stimulates secretion of bile and bilirubin and may be useful in correcting high tyramine levels in patients with liver cirrhosis.[5]