Source : Webster's Revised Unabridged Dictionary (1913)

Yellowwort \Yel"low*wort`\, n. (Bot.)
   A European yellow-flowered, gentianaceous ({Chlora
   perfoliata}). The whole plant is intensely bitter, and is
   sometimes used as a tonic, and also in dyeing yellow.

Centaury \Cen"tau*ry\, n. [L. centaureum and centauria, Gr. ?,
   ?, and ?, fr. the Centaur Chiron.] (Bot.)
   A gentianaceous plant not fully identified. The name is
   usually given to the {Eryther[ae]a Centaurium} and the
   {Chlora perfoliata} of Europe, but is also extended to the
   whole genus {Sabbatia}, and even to the unrelated
   {Centaurea}.