vernonin

from The Century Dictionary.

• noun A cororless, pulverulent compound, C₁₀H₂₄O₇, contained in the root of Vernonia Nigritiana. It is used on the west coast of Africa as a febrifuge and is a cardiac poison, 80 parts of it producing the same effect as one part of digitalin.

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

• noun (Chem.) A glucoside extracted from the root of a South African plant of the genus Vernonia, as a deliquescent powder, and used as a mild heart tonic.

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

• noun organic chemistry A glucoside extracted from the root of a South African plant of the genus Vernonia, used as a mild heart tonic.