XANTHORHIZA

Xan`tho*rhi"za, n. [NL., fr. Gr. xanqo`s yellow + "ri`za root.] (Bot.)

Definition: 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.

Source: Webster’s Unabridged Dictionary 1913 Edition