Verbena
Verbena, a genus of about 75 species of plants, chiefly shrubs and annual and perennial herbs. Most verbenas are native to tropical America, but about 25 species grow in North America and a few are native to Europe.
Verbena has clusters of vivid, five-petaled blossoms on a slender stem.Blue vervain, of North America, grows three to five feet (90 to 150 cm) tall. It produces slender flower spikes arranged like candelabra. The tiny blue or white flowers bloom and die from the bottoms of the spikes upward. White vervain, also of North America, grows as tall as blue vervain. It bears white, blue, or lilac flowers in slender, upright spikes.
European vervain, a common weed in North America, grows up to three feet (90 cm) tall and bears spikes of pale purple or white flowers. It was associated with the worship of the ancient Druids and with witchcraft, and was long believed, mistakenly, to have medicinal properties. Garden verbena, native to Brazil, grows about two feet (60 cm) tall and bears dome-shaped clusters of large, fragrant flowers in a wide variety of colors.
Blue vervain is Verbena hastate; white, V. urticaefolia; European, V. officinalis; garden, V. hortensia. All are of the family Verbenaceae.