Yellowroot carries a Latin name that gives the whole thing away: xanthos and rhiza, yellow root. Cut a piece and the interior is a startling chrome yellow, the source of a dye and of a bitter tonic in Appalachian home medicine. Above ground the plants are quiet and low, a knee-high thicket of celery-like leaves that turns bronze and gold in autumn.

Xanthorhiza simplicissima is a buttercup relative that behaves nothing like one, spreading by slow rhizome along stream banks and shaded slopes to hold ground that would otherwise wash. The flowers are tiny, brown-purple, and easy to miss in early spring. This is a plant for the difficult shaded bank, the erosion problem, the place under trees where grass will not go, and one of the few natives that solves that problem without taking the whole garden.