Xanthorhiza
Xanthorhiza , noun
[New Latin, from Greek xanqo`s yellow + "ri`za root.]
(Botany) A genus of shrubby ranunculaceous plants of North America, including only the species Xanthorhiza apiifolia, which has roots of a deep yellow color; yellowroot. The bark is intensely bitter, and is sometimes used as a tonic.