Xanthoriza simplicissima. Yellow root is native of the Eastern United States and is a member of the buttercup family. Striking characteristics are its vibrant yellow root as the name describes, and fern-like leaves, as well as attractive fall foliage. It matures at 2-3 feet in height. Yellow root thrives in well-drained, acidic soils, but can grow in neutral to alkaline soils. Planting medium should be rich in organic matter with some sand and clay. Zones 3-9.
Photo credits:
Fall foliage: Krzysztof Ziarnek, Kenraiz photo via ncwildflower.org
Yellowroot flowers: Lisa Tompkins via ncwildflower.org