Xanthorhiza simplicissima aka Yellowroot

Xanthorhiza simplicissima, or yellowroot, is a small, leaf-shedding shrub. It belongs to the buttercup family, Ranunculaceae. Its native range spans the eastern United States to eastern Texas. Wild plants grow beside streams and in damp woods. They also occur in thickets and on rocky ledges. This low woodland plant spreads through suckers and forms clumps.

Garden plants stand about 0.5–3 feet [0.15–0.91 metres] tall. RHS gives an upper height of 3.3 feet [1 metre]. Clumps can spread 6–10 feet [1.83–3.05 metres] across. In good conditions, their spread has no fixed limit. The upright stems lack branches and bear leaves near their tips. Thin, smooth bark has brown and gray tones. The roots are yellow, which explains the common name. Glossy green, pinnate leaves have three to five leaflets. Each leaflet has lobes and teeth along its edge. Fall leaves turn yellow, orange, red, or purple. Some sun helps bring out their fall color.

Small flowers hang in branched panicles as spring leaves open. They have a star shape and brown-purple to maroon tones. Five sepals surround each flower, which has no petals. North Carolina State records flowering from March through May. The flowers add less garden interest than the fall leaves. Green follicles form star-like fruit clusters and dry to yellow. These fruits appear in May and June. Birds and small mammals eat them. The plants also give wildlife cover beneath taller growth.

Yellowroot grows best in moist soil that drains well. It favors acid soil with plenty of humus. Partial shade suits it, but it also accepts deep shade. It tolerates clay and spells of wet or dry soil. Established plants can withstand drought and grow in dry shade. Sources give USDA zones 3–9 and the UK rating H6. Use it beneath trees, along pond edges, or on banks. Its spreading growth helps hold soil on slopes. Metal edging or a concrete path can limit its spread.

Alkaline soil can cause chlorosis, leaving the foliage pale. Sources report few serious pest or disease problems. Deer tend to leave the plant alone. Roots and stems yield yellow dye; stems have served in basketry. Native Americans used the roots as a dye source. Traditional medicine has also used the roots for several ailments. These uses do not establish that home remedies are safe. No edible uses are known. Large doses of the root may be toxic.