VERBENA, VERVAIN; a genus of the monogynia order, belonging to the diandria class of plants. There are 18 species; of which the most remarkable is the officinalis, or common vervain, growing on the road-sides near towns and villages. The leaves have many jagged clefts, the blossoms are pale blue. It manifests a slight degree of astringency, and was formerly much in vogue as a deoblitruent; but is now disregarded. Mr Millar says that it is never found above a quarter of a mile from a house; whence the common people in England call it Simpler's joy, because wherever it is found, it is a certain sign of a house being near. Sheep eat it; cows, horses, and goats, refuse it.