yellowwort

from The Century Dictionary.

• noun A European annual plant, Chlora perfoliata, of the gentian family.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Blackstonia perfoliata, a gentianaceous plant with bright yellow flowers.