A plant genus of the family LAMIACEAE. Members contain teuscordonin. There have been reports of hepatoxicity by this genus.

A plant genus of the family LAMIACEAE used in folk medicine as a nervine.

A plant genus of the family ASTERACEAE that has long been used in folk medicine for treating wounds.

Oils which evaporate readily. The volatile oils occur in aromatic plants, to which they give odor and other characteristics. Most volatile oils consist of a mixture of two or more TERPENES or of a mixture of an eleoptene (the more volatile constituent of a volatile oil) with a stearopten (the more solid constituent). The synonym essential oils refers to the essence of a plant, as its perfume or scent, and not to its indispensability.

The presence of organisms, or any foreign material that makes a drug preparation impure.