What does "verbena" mean?

Verbena: A genus of herbaceous plants of which several species are extensively cultivated for the great beauty of their flowers; vervain. Note: Verbena, or vervain, was used by the Greeks, the Romans, and the Druids, in their sacred rites. Brewer. Essence of verbena, Oil of verbena, a perfume prepared from the lemon verbena; also, a similar perfume properly called grass oil. See Grass oil, under Grass. -- Lemon, or Sweet, verbena, a shrubby verbenaceous plant (Lippia citriodora), with narrow leaves which exhale a pleasant, lemonlike fragrance when crushed.