Xanthorhiza simplicissima, commonly known as yellowroot, is a low-growing, deciduous woody shrub native to the eastern United States.

It belongs to the buttercup family (Ranunculaceae) and is the only member of its genus.Its name perfectly describes its anatomy: Xanthorhiza translates from Greek to "yellow root", while simplicissima refers to its "most simple" unbranched stems.

It typically reaches 1 to 3' tall and spreads horizontally via underground suckers to form a dense, mat-like groundcover. The glossy, bright green leaves have a feathery, celery-like appearance.

In autumn, the foliage transitions into striking shades of yellow, bronze, and reddish-purple.

In early spring, tiny, star-shaped, purplish-brown flowers bloom in drooping clusters at the base of the leaves. These are followed by small, dry, yellowish-brown seed follicles.

Stripping the smooth outer bark reveals a vibrant, deep-yellow inner bark and root system that tastes intensely bitter.

Because it spreads clonally and thrives along stream banks, river shores, and damp slopes, it is highly valued for soil stabilization and bank restoration.Landscaping: It serves as an excellent, low-maintenance groundcover for woodland gardens, shaded borders, and rain gardens.

It is notably deer-resistant.

Native Americans and early settlers extracted the chemical compound berberine from the roots to produce a strong yellow dye. It was also utilized in traditional medicine to treat gastrointestinal distress, mouth sores, and colds.